M42club.com - Home of the BMW E30/E36 318i/iS
DISCUSSION => Electrical => Topic started by: Cobra Jet on April 21, 2008, 08:33:37 PM
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Ok - here's where I am at...
Drove the car into work this morning and it started/ran fine. Upon leaving at the end of the work day, I went to start the car and it would only crank over (starter works, battery is fine, etc). I tried a few more times, the car would not start. I did the pedal test to get any CEL codes, nothing, CEL spit back 1444.
So, I turned on the key again and listened for the fuel pump (my rear seat is out since I've been cleaning out the interior of the car). With the seat out, of course it's very easy to hear the sound of the pump. With the key turned to on, no fuel pump whine at all. I even put my hand over the pump cover to feel any vibrations from the pump, nothing. I had to have the car flat bedded from work back to home since I could not start it and needed a transport back to home...
I've been scouring threads on here about fuel pump, fuel pump relay and non-start issues.
I took the black engine cover off the main/fuel pump/O2 relays and put my hand on the 3 relays there. I turned the key to on and did feel a "clicking" sensation from the relay bank. I'm not sure if all 3 are clicking or if only 1, 2 or ? are clicking....
I started by turning on the key again with the pump cover off to hear anything from the pump area - nothing. So, I removed the pump from the tank, created a (-) & (+) jumper wire and took the pump over to the battery. I hooked the -/+ leads directly to the battery (in correct order) and then directly to the proper connections on the fuel pump. The pump operated immediately, seemed to spin w/ full force and spit fuel onto the ground (this was about a 3-4 second test). I am deducing from this test that the fuel pump is working fine (right or wrong?)....
I then grabbed my multi-meter and tested the fuel pump harness in the car. I probed the harness, turned the key to on and watched the multi-meter. I did this 6 times... Each time I saw the voltage read 12v+, then drop back below 12v slowly. Is that supposed to happen? I am assuming by the test that I did (if correct), shows that I am getting voltage to the pump? However, when I hook up the connector back to the pump and go to start the car, I get no pump prime.
What I am really puzzled about is that the pump worked 100% while being hooked directly to the battery, but won't work once reinstalled into the vehicle!!??!! If I am getting voltage at the connector (assuming I did the voltage test correctly), should'nt this kick on the fuel pump?
I tried doing the fuel pump relay jumper - but I'm not sure if I am doing it correctly... I jumped position #30 and position #87 in the relay block and did not hear anything from the pump.... Should the key be turned on for this test? If not, how am I to know what's going on with the jumper?
If when doing the jumper I don't hear the fuel pump kick on - what else should I be looking at or for?
I'm at a loss right now... and scouring threads on here and the net is making my freaking head hurt.
The car only has 100k on it and was (has been) running fine (with the exception of cleaning out the ICV, which made the car run even better).
I saw a thread about testing position #30 on the fuel pump relay socket - how do I do this test (meaning, what do I probe and how do I probe it) - this was to test for 12v in that socket...??? The thread was not clear at all, it just said to test for 12v at socket #30, but no info as to how to actually do the test.
I also checked the entire fuse block for any blown fuses and do not see any blown fuses. Is the fuel pump fuse #11???
Any ideas fellas, I really need help on this one. I've been doing all the searching I can...
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The relay needs to sense crank movement. If the cranksensor is defective you wont start. I dont know hot to diagnose the sensor. In my case the pump was gone. Did not pump when doing the same u did. My 2 cents would be the cranksensor.
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The relay needs to sense crank movement. If the cranksensor is defective you wont start. I dont know hot to diagnose the sensor. In my case the pump was gone. Did not pump when doing the same u did. My 2 cents would be the cranksensor.
If the crank sensor was or is bad though, shouldn't I be getting a fault code and a CEL from the DME??? I don't have any stored fault codes, the CEL is not illuminated and when I extract codes, I'm only getting the 1444 (no fault codes). I would surely think that if the crank sensor crapped out, I would definitely get a stored code and also a CEL for that part, right?
I can crank the car over, but the fuel pump is not firing up when reconnected to the harness/connector in the vehicle.
Can someone please go over the relay testing again with me?? Am I testing the wrong way?
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I concur, it may very well be the crank position sensor, but to confirm that you are in fact getting power to the pump, let's go over how the start circuit works for the fuel pump (as I understand it, anyway!).
Power comes from the junction block down the yellow line to the DME all the time, but the DME doesn't send it into the starting circuit until it senses that you have the key on. So, the blue, green, and red lines have power, but aren't doing anything with it yet.
(http://lh5.ggpht.com/2006TopBanana/SA3XhzBQMrI/AAAAAAAADVY/zBRY2rCf3_U/s800/start1.jpg)
When you turn the key to the ON position, it grounds the green line at port 27 (Main Relay Control), causing the green line to have power all the way through the main relay via tabs 85 and 86.
(http://lh4.ggpht.com/2006TopBanana/SA3XijBQMsI/AAAAAAAADVg/uKC6lo3g0QU/s800/start2.jpg)
This energizes the coil and pulls the relay closed, sending power through the main relay from tab 30 to tab 87, and from there to (among other places) the fuel pump relay's tab 86. But the fuel pump relay's tab 85 is still not grounded, so power doesn't go through yet.
(http://lh6.ggpht.com/2006TopBanana/SA3XjDBQMtI/AAAAAAAADVo/wiEspi_6oe0/s800/start3.jpg)
The DME checks to make sure that the engine is rotating using the crank position sensor - when it sees that the engine is in fact moving, it grounds the fuel pump relay control at port 1, completing the blue circuit.
(http://lh6.ggpht.com/2006TopBanana/SA3X4DBQMuI/AAAAAAAADVw/xogXcUzCXUA/s800/Start4.jpg)
Now that the blue circuit has power going through it, the fuel pump relay coil pulls in, energizing the red line and sending power through tabs 30 and 87 to fuse 11.
(http://lh4.ggpht.com/2006TopBanana/SA3YEjBQMvI/AAAAAAAADV4/XZVOXo-4-0M/s800/Start5.jpg)
Assuming fuse 11 is good, power goes to the fuel pump, and it starts pumping fuel.
If the crank position sensor is malfunctioning, the DME won't know that the engine is turning, so it won't turn on the fuel pump.
So, to systematically test and make sure that the circuits are working as they should, start with a fused jumper wire at the fuel pump relay. I actually use a switched, fused jumper, so I can turn it on and off from the engine area. For all of these tests, when I say 'ignition on' I mean in the RUN position, not the ACCESSORY position.
First, exchange fuse 11 with another fuse (same or lower amp rating, never higher). Just in case the fuse is bad, but still looks OK. It's rare, but it does happen. See if it will start. If not...
Remove the fuel pump relay. Insert one end of your jumper wire into the hole where tab 30 goes, and the other end into the hole where tab 87 goes. With the ignition on, the pump should start pumping. If it does not, but your fuel pump works when hooked directly to +12V, then you have a problem in the wiring between the fuel pump relay and the fuel pump.
If that works, but it doesn't when the relay is in, you may have a bad relay. You can test the relay by applying +12V to tab 86 and grounding tab 85. Now check continuity between tabs 30 and 87 - there should be virtually no resistance. If there is a lot of resistance, or there is no continuity, replace the relay.
If the relay works, it may very well be the crank position sensor. Get out your multimeter and check the hole where tab 86 of the fuel pump relay goes. With the key on, there should be +12V there. If there is, then I would strongly suspect the crank position sensor.
If there isn't, you'll have to do the same tests on the main relay.
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ak96ss
You must work for NASA !!!!!!!!!!!!
Very well done.......Might be cps.
Put an ohm meter on the crankshaft position sensor .You should have 650 ohms +-.Bentley manual says 1250 but that is for camshaft position sensor .
(http://i141.photobucket.com/albums/r73/bogeyman700/bmw/cps.jpg)
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What is the value of the fuel pump relay (in the event it is bad)? Meaning, can I purchase a 4-pronged relay at an auto parts store that is the same design/value instead of having to order such relays from an online vendor (or buying from a Dealer)?
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Thanks for the help fellas, it's GREATLY appreciated. I'll have to perform more tests when I get home today...
Just curious - is it common for the CPS to crap out but NOT induce a CEL or code into the DME? Just wondering why I don't see any stored codes for a bad CPS (if that could be the issue)...
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Where are you folks buying your crankshaft positioning sensors from?
I've checked BMA - nothing is listed (not for crank sensor, crankshaft sensor or reference sensor). I also checked bimmerparts, bimmerzone, oem-bmw-parts and they don't have the 318 M42 crankshaft or camshaft sensor available.... ???
What vendor has the best price & service for such parts? I don't want to have to resort to Dealer pricing...
I want to know in advance just in case my testing later results in having to order a new CPS...
THANKS!
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try autohausaz.com (http://www.autohausaz.com/search/product.aspx?sid=peifymruxffysv3o44o5nwbq&makeid=800003@BMW&modelid=1011249@318I&year=1991&cid=sensor@sensor&gid=7192@Camshaft%20Position/Reference%20Mark%20%20Sensor)
part # 12141721861
item 6 is what i think you are looking for.
http://www.realoem.com/bmw/showparts.do?model=AF93&mospid=47305&btnr=11_2683&hg=11&fg=10&hl=19
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try autohausaz.com (http://www.autohausaz.com/search/product.aspx?sid=peifymruxffysv3o44o5nwbq&makeid=800003@BMW&modelid=1011249@318I&year=1991&cid=sensor@sensor&gid=7192@Camshaft%20Position/Reference%20Mark%20%20Sensor)
part # 12141721861
item 6 is what i think you are looking for.
http://www.realoem.com/bmw/showparts.do?model=AF93&mospid=47305&btnr=11_2683&hg=11&fg=10&hl=19
That is the camshaft sensor. The crank sensor is on the lower timing cover case near the crank. :) Most places like autohauz only seem to reference the camshaft sensor and no crank sensor..
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What is the value of the fuel pump relay (in the event it is bad)? Meaning, can I purchase a 4-pronged relay at an auto parts store that is the same design/value instead of having to order such relays from an online vendor (or buying from a Dealer)?
Typically, different pinout. The tabs are in different spots, so even though they are oriented the same way and it will plug in, the relay you get from Manny, Moe and whoever won't work.
Try 12141721968, Pulse Generator, I think that is the right one. If it doesn't show in the online catalog, you can still email or call Yves or Patrick at BMA and they can get the part for you, probably cheaper with shipping than your local dealer.
Expensive, though, so I would make sure that is the one you need before you order it!
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http://www.bavauto.com/shop.asp
169.00 bucks
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MORE UPDATES:
Ok, so I've done some more poking, prodding, reading, searching, researching and diagnostics on my 318ic non-start issue....
Here's what I have confirmed to date:
1) when the fuel pump is removed from the tank and is hot wired to a battery, it DOES power up & work
2) when the fuel pump is in the tank and is hot wired to a battery jumper box, again the pump DOES power up & work
3) once the fuel pump relay is removed and jumping the fuel pump relay sockets at the firewall (contacts #30 & #87), the fuel pump DOES power up & work
4) there IS voltage at the female 2-pronged fuel pump harness connector at the fuel pump
5) #11 fuse (for fuel pump) in the main fuse box under the hood IS good (not blown)
6) when the fuel pump was hotwired at the tank and was operating, while cranking over the car, it still would NOT start
So, based on the above, I have confirmed that the fuel pump and associated wiring/connectors/relay socket are NOT the issues, would you all agree?
Now, I have been reading LOTS of threads on this site, on bfc, on r3v, on bimmermania, etc etc etc... and I just need to confirm with some of you the below diagnosis before placing an order for the part.
After working through the steps outlined above, I then read that if performing all of the above and all of those tests come out POSITIVE the next step would be to test the CPS function. By doing this, you pop off a plug wire, insert a spark plug into that wire and ground it to the engine or body and have someone crank over the vehicle. If when cranking over the vehicle there is NO spark seen from that plug, then it is possible that the problem could be the CPS (crank positioning sensor).
So, I performed that step as well. I removed the plug wire at the front of the engine, inserted a good spark plug into the end of it and had someone crank the car over while I looked for an ignited spark. My grounding point for this test was the nuts @ the strut tower, as I could not get a good ground off the valve cover of the engine because the valve cover is powder coated. When the engine was cranked over, I did not see any spark whatsoever, nothing. I moved the spark plug around to different grounding points and again I could not get or see any spark at all.
Was I performing the above CPS test correctly?
Based on the CPS test and confirmation of not getting any spark, would it be safe to say that my non-start issue IS POSSIBLY a bad CPS??
The only (2) tests I have not performed with relation to determing a non-start issue was seeing if there was power to the #30 socket at the fuel pump relay connection at the firewall and also testing the actual fuel pump relay. The only reason I did not do these minor tests was because based on my testing for 1-6, I have determined that the issue is not the fuel pump or the wiring/relay point, because I was able to get the pump fired up after performing multiple tests. Would you agree that if steps 1-6 ruled out a faulty pump there is no need to do these 2 tests?
Have I missed ANY diagnostic tests that I SHOULD be doing, before ordering up the CPS?
The only reason I ask is based on all of the testing I have done so far and based on what I have read with regards to MANY different types of non-start issues, many on here and on other sites have said if the CPS is faulty, 1) there would not be any spark and 2) if the DME & associated relays do not sense a spark, there will be no fuel....
I just want to be sure that the part I am about to order is THE part that will get me up and running again - after all, these CPS's are not cheap.
Am I leaving anything out or have I missed anything crucial in my diagnosis?
The only thing I'm still curious about is why I am not getting ANY CEL for a bad CPS? Any ideas on this one? I thought if such a sensor were to fail that the DME would "see" this failure, log a code and throw a CEL? Have any of you who did replace a CPS get a stored fault code from the DME or not?
Thanks again for any/all help with regards to this issue...
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Why haven't you done the cps test I indicated above ?????
That will tell you if the cps is bad.Everything you've done so far is good and does indicate to a bad cps but you have to test the cps itself to confirm that it is bad.
good luck
I do have an old cps that was working when I removed it from my car.
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Good job - so now we now it is not the fuel pump wiring. Number 3 there solved the wiring issue. You could still have a bad relay, though, unless I missed the part where you checked that, but given the lack of a spark, I'd get that fixed first.
Unfortunately, there is no way to say for certain from here whether the problem is the CPS or not without you testing it - what you have is a 'no spark' condition, which could be a bad DME, a bad CPS, faulty wiring to the coils, etc. In other words, there are lots of reasons that the spark plugs could not fire.
Honestly, your best bet is to borrow a known-good CPS and try it out before sinking the money in the part. It would suck to spend that kind of money on a part that is not faulty, and then have to buy something else. Throwing parts at a problem is not a good way to work unless you just like having something to spend your money on, like me. :)
Do you get no light at all for the CEL, or does it just give you the 1444 code?
EDIT: Nevermind, I see that you are getting a 1444.
And, have you seen this thread? http://forums.bimmerforums.com/forum/showthread.php?p=12421117
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Why haven't you done the cps test I indicated above ?????
That will tell you if the cps is bad.Everything you've done so far is good and does indicate to a bad cps but you have to test the cps itself to confirm that it is bad.
good luck
I do have an old cps that was working when I removed it from my car.
LOL -I WOULD have done the CPS test as in this thread, however, last night (and all day yesterday) I could not get onto this site, I kept getting a DNS error (I started a thread in the general section on here about that issue...). I run out of daylight to work on the car, so I've also been working with limited time after getting in from work and I concentrated on the fuel pump diagnosis first over the last couple of days.
So, being without the ability to get to this thread, I did not know which contacts to probe or what my OHM reading should have been. I did pull the plug off and checked it out, but other than that, I was seeing varying info from others on other forums of which many stated many different operating OHM variations for this sensor... So I was completely unsure of what would be the correct operating range or not.
By chance if this is the culprit - could I buy your working sensor if it's low mileage, or would you just recommened buying new based on possible used failure rate?
Is a new O-ring really needed for installing another CPS? I'm asking because based on the info in the manual you posted above, it states to use a new O-ring.
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Do you get no light at all for the CEL, or does it just give you the 1444 code? EDIT: Nevermind, I see that you are getting a 1444.
And, have you seen this thread? http://forums.bimmerforums.com/forum/showthread.php?p=12421117
Yes, the CEL does light up upon start up or if the key is turned "on". I also did the pedal test multiple times after trying to start it and I only get the no fault code 1444.
As for the linked thread, as a matter of fact, I had replied to that thread to assist the members in it, then was struck with this non-start issue only a few days afterwards... LOL!
I asked in that thread today, might as well do the same here - is the fusible link they are referring to located in the same location on a 91 318ic? The only reason I am asking is my battery is not mounted in the trunk, it's factory location is under the hood. Therefore, I'm only guessing that my fusible link they are discussing will not be in the trunk location, but possibly up front under the hood...? If it is located up front, where should I be able to find this fusible link? I'm wondering if that could be an issue on my vehicle as well... and if so, why...
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LOL -I WOULD have done the CPS test as in this thread, however, last night (and all day yesterday) I could not get onto this site, I kept getting a DNS error (I started a thread in the general section on here about that issue...). I run out of daylight to work on the car, so I've also been working with limited time after getting in from work and I concentrated on the fuel pump diagnosis first over the last couple of days.
So, being without the ability to get to this thread, I did not know which contacts to probe or what my OHM reading should have been. I did pull the plug off and checked it out, but other than that, I was seeing varying info from others on other forums of which many stated many different operating OHM variations for this sensor... So I was completely unsure of what would be the correct operating range or not.
By chance if this is the culprit - could I buy your working sensor if it's low mileage, or would you just recommened buying new based on possible used failure rate?
Is a new O-ring really needed for installing another CPS? I'm asking because based on the info in the manual you posted above, it states to use a new O-ring.
My sensor probably has at least 150K on it.When I tested mine the meter said 650 ohms when the manual says 1250 so I got a new one and when I tested the new one I discovered it said 650 also so I knew that the manual was incorrect . I searched on bimmerforums and found that this was indeed true. So I replaced my good sensor with a brand new one .
As far as the o ring ,either get one at an auto store or use your old one.If you have ac in your car it makes it hard to install the sensor cause the wiring goes behind the bracket IIRC . So the bracket must come off.
First things first ................ determine if indeed the sensor is faulty.
When these cars are sorted out and maintained they are a fun reliable vehicle.
good luck
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What happens when you start the car with the CPS disconnected? CEL?
Did you ever replace the ICV?
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I looked at my car last night and I don't believe there is an O ring for the cps??
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I looked at my car last night and I don't believe there is an O ring for the cps??
crank ps = no oring
cam ps = oring
crank ps hangs on an external bracket.
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ICV is working fine, it's buzzing when the key is turned to "on" and when hot wired, it works w/o issues after cleaning it last weekend, it also tested good OHM's. The car started and drove fine after the ICV was cleaned. Like I said above, I drove it into work, it sat for 8+ hours, I came out to leave and it would not start, just kept cranking. The fuel pump was not (and is not currently) getting any power when the car is trying to be started up. The only time the pump gets power is if I hot wire it directly to a battery jump box or jump the fuel pump relay sockets 30/87.
The car is definitely not getting any spark, as when I did the spark plug test, I saw no spark at all....and that's when and after I posted my above updates.
I've not had time to do any other or further tests to the CPS, DME relay, coils or DME...
I would *think* that if the CPS is unplugged that the DME should log a code, right? I could try that idea out too by unplugging the CPS and seeing if the DMW will store a fault code. I'm just puzzled as to why the DME does not have ANY stored fault codes at all. All I keep getting is "1444", even after trying to start the car over and over and over....
I'm going to try and go at it again when I get home, depending on how much daylight I have left. The thing is just sitting out in front of the house where the flat bed left it and I don't have the man power to push it up the driveway into the garage.
(thanks for O-ring clarification)
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I'd be curious to see if it will throw a CPS fault with it unplugged. If it doesn't, that should bring you closer to an answer. :)
Try removing or wiggling the line and see if it makes any difference. Could be damaged internally but moving it around might get you different results.
Are there 2 pumps on this car? Never looked into it. There are 2 on my 325ic.
Sorry haven't been much help to anyone lately. Too busy at work (eating while I type this).
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Are there 2 pumps on this car? Never looked into it. There are 2 on my 325ic.
Sorry haven't been much help to anyone lately. Too busy at work (eating while I type this).
No, according to all online info (threads, tech, manuals, etc), there is only a single in-tank EFI fuel pump. Some of the earlier E30's (like your 325) had 2 pumps, 1 internal and 1 external.
no new updates, car still sitting.
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Have you tested fuel pressure after the fuel filter, or even at the fuel rail? Unfortunately you don't have a schraeder valve (which would make it real easy), so it's a litte pain if you test at the fuel rail. But testing after the fuel filter would be easy.
I don't know if the fuel pressure sensor does not pick up good fuel pressure if it would stop spark to the cylinders. If it does, then your problem could be as simple as a clogged fuel filter.
My money is still on the crank ps though.
A faulty crank ps might not show up on your cel, but a BMW GT1 machine might pick it up. I might be in the future on this one since I'm far from sure, but I thought that might explain the lack of cel when the cps sensor is bad.
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ANOTHER UPDATE (car still not running):
Here's where I am at (besides being totally frustrated and not being able to drive the car) - these are the lastest diagnostic tests I have performed last night:
1) I looked at the existing fuse #11 in the main fuse box, it was good and not blown - so just to double check, I replaced that fuse with another known good fuse of the same exact value, still no start
2) pulled fuel pump relay and tested it by applying 12v directly to tab #86 and grounded tab #85 of the actual relay - the fuel pump relay then "clicked" or powered itself "on".
3) I probed the hole for position #86 where the fuel pump relay plugs into and the readout displayed 11.85v
4) I then tried to test for continuity between tabs #30 & #87 on the fuel pump relay - when I did this, I did not see any readout displayed on my multimeter, nor did I hear any audible "beep" from it. Should I have seen a readout on the display? Does "no continuity" mean I would not see any readout and if there was continuity, I would have seen a readout? Should the relay have been "powered on" as in step 3 above and then tested for continuity?
5) After the fuel pump relay testing above, I then pulled another "exact" relay (confirmed as a working relay as well) from the main fuse box and inserted it into the fuel pump relay slot - still no start with another working relay.
6) I pulled off the end connector of the CPS and tested the resistance of it. My digital multimeter went up to 1.180 OHMS and was slowly stilll ticking up by 1 digit each time (ie: 1.180, 1.181, 1.182, etc) and I stopped the test at that point. Now, I'm not sure if this is "good" or "bad" - only because of the various threads I have read on this site and many others that state the BMW Bentley Manual has the INCORRECT parameter for this sensor. From what I have read, this sensor should only be reading .650 +/- 10%.... The Bentley states "1280 +/- 10%". I don't see ANY exterior breaks in the CPS harness, no breaks at the plug end and no breaks at the sensor end at the crank. Now, based on my reading posted here for the CPS - can someone PLEASE tell me if my reading is showing a bad or good sensor???
7) I also pulled the plug on the Camshaft Positioning Sensor and tested it as well - just to see what it was reading. My multimeter showed .990 OHMS, it did not fluctuate at all - an instant .990 reading as soon as I put my multimeter probes on contacts 1 & 2 at the plug end. Is this a good reading for the Camshaft Positioning Sensor? What are the parameters of this sensor? Did I test it correctly?
8) All of the fuses in my fuse panel are all good, no blown fuses at all.
9) I then pulled off the CPS plug and let it hang and tried to start the car to see if the DME would register a no fault code for a non-functional/missing sensor. I cranked it over multiple times. The DME still did not pick up or store any fault codes, I still get a "1444" no fault code out of it. I'm still puzzled as to why the DME is not picking up or storing any fault codes...
So, just to recap -
1) fuel pump is not kicking on when ignition is used
2) the fuel pump DOES work when power is hooked directly to it
3) the fuel pump DOES work when relay slots #30 & #87 are jumped at the fire wall w/ key on (should it do the same w/ key off?)
4) the fuel pump relay seems to be good per the above tests
5) fuel pump relay slot #86 is getting 12v
6) there IS power at the end of the fuel pump harness at gas tank
7) #11 fuse for the fuel pump IS good
8) DME is not storing any fault codes
9) there is NO spark when pulling plug wire, attaching spark plug to end of it, grounding spark plug and starting vehicle
I'm not sure about my CPS readout - can someone tell me if what I'm seeing as the OHMS for this sensor is bad or good and what the correct parameter really is? The last thing I want to do is drop close to $200 on a CPS sensor and that not being my non-start problem. IF the parameter is DOUBLE that of what it should be (my 1.180 as opposed to the supposed .650), does this mean the sensor is bad?
Can someone also tell me how to do or test the below:
A) DME relay - I think I probed the correct hole for the DME relay (is the DME relay to the LEFT or RIGHT of the fuel pump relay and what color is it???) The hole I probed was I think tab #86 or #30 (can't remember at this point) w/ ignition "on" and I saw the same 11.85v readout as when I probed the same slots for the fuel pump relay. I did NOT test the actual DME relay though, because I still have not come across tech or a thread showing how to test the DME relay. Can someone please tell me how to go about testing the DME relay - or testing the DME relay slots at the firewall?
B) How do I test to see if power is getting to the actual DME? I have not been able to find a good thread about this procedure.
C) Where are the fusible links located on a 1991 318ic??? The factory battery location on this vehicle is under the hood on the passenger side... I know the coupes/sedans have the battery in the trunk and fusible link locations are completely different. Can someone point me in the right direction here so I can also check for any possible blown fusible links for a 1991 318ic?? How does one tell if a fusible link is blown, is there a visible physical characteristic to look for, does it need to be tested?
and lastly -
CAN SOMEONE PLEASE LEND ME A CONFIRMED WORKING CPS AND DME so I can see if the loaner parts WILL start my vehicle? You can carve your name in the parts, label them, mark them, whatever - I am 100% trustworthy and WILL return the said parts to you 100% in the same exact condition as loaned... I can supply TONS of references if needed, I'm on multiple automotive forums w/ tons of post counts and have over 1,000+ positive feedbacks on eBay as well... Can someone PLEEEEEEASE help me out?
I just REALLY NEED to get this car up and running again and I've been searching numerous threads, links, forums, googling and trying to test for nearly everything to determine why it's not starting...
I APPRECIATE ALL of the help from ALL of you too.
Are there any other non-start diagnostic tests I am overlooking or have not done yet?
If anyone else has any more info or help, PLEASE DO ADD IT to this thread - this is most likely the ultimate diagnostic thread for a non-starting M42... :cool:
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Send me a PM with your mailing address and I'll send you my extra cps to try.
I'll put an ohm meter on my extra cps and the one in my car tomorrow and tell you what it reads although I already know it will read 650 .
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Well ,I just went out and tested .
1) extra crank ps = 500 ohms
2) crank ps in good running car = 525 ohms
3) extra camshaft ps = 1190 ohms
4) camshaft ps in good running car = 1200 ohms
If you still want to try or buy or try and buy my cps PM me.
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If your check engine light comes on when you turn the key on (but before you start the car) then the DME should be getting power.
A relay is a relay is a relay (generally speaking!) - you test the DME relay the same way you test any other relay.
Fusible link is just a wire that will burn up if it gets too much current, kind of like a fuse. If you can find it (and I don't know where it is on an -ic, but it should be right at or near the positive battery terminal), follow it along and see if there are any parts of the wire cover that are melted or burned.
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If your check engine light comes on when you turn the key on (but before you start the car) then the DME should be getting power.
A relay is a relay is a relay (generally speaking!) - you test the DME relay the same way you test any other relay.
Fusible link is just a wire that will burn up if it gets too much current, kind of like a fuse. If you can find it (and I don't know where it is on an -ic, but it should be right at or near the positive battery terminal), follow it along and see if there are any parts of the wire cover that are melted or burned.
Yes, when I turn the key "on", the CEL does illuminate for sure (stays solid). I'm also assuming it's getting power if I'm able to do the pedal/code extraction test?
What's your thoughts as far as it not storing any fault codes for a non-start?
As for the fusible links, I'll have to look for them, as I did not have any time tonight to look.
I read on B.Purcell's site that the (3) relays on the 318/M42 firewall are in this order (according to his site text and I'm ASSUMING if looking at the car while standing directly in front of it) -
1) LEFT = O2 sensor relay
2) MIDDLE = Fuel pump relay
3) RIGHT = DME relay
Here is the exact quote from his site:
Relays
The ignition relays are mounted on the engine side of the firewall. The one on the right is the DME relay, the middle one is the fuel pump relay and the left one is the oxygen sensor relay (if fitted).
What I am confused about is other threads or sites I have see or read, it seems others have stated the DME and O2 relays in the opposite slots - meaning different from what Brandon states on his site... ??
Can someone confirm the DME & O2 relay locations?
I'll retest the 2 remaining relays (O2 & DME) - I'm assuming I test them in the same manner - 12v to #86, ground #85 - and check for continuity @ #87 & #30??
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Thanks very much for all the help (again), it's appreciated.
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Well ,I just went out and tested .
1) extra crank ps = 500 ohms
2) crank ps in good running car = 525 ohms
3) extra camshaft ps = 1190 ohms
4) camshaft ps in good running car = 1200 ohms
If you still want to try or buy or try and buy my cps PM me.
REDIS91 -
I PM'd you. (thanks!)
Also, do you feel that my Camshaft position sensor is within reasonable range (as noted in my earlier thread above)?
Would you think that my CPS sensor is corrupt since it's reading way above the "norm"?
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REDIS91 -
I PM'd you. (thanks!)
Also, do you feel that my Camshaft position sensor is within reasonable range (as noted in my earlier thread above)?
Would you think that my CPS sensor is corrupt since it's reading way above the "norm"?
I will send you both my sensors crank and cam.Try the crank ps first and see if that solves your problem .I think it will .Also here is a pic of the relays .
good luck
(http://i141.photobucket.com/albums/r73/bogeyman700/bmw/fuses001copy.jpg)
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Crank sensor is a magnetic sensor, is it not? Is it fair to say the resistance will vary depending on whether or not the sensor is inline with a tooth on the gear? Never tried it...just thinking out loud.
I would pull the sensor out of the bracket, enough to keep it away from something metal and test it again.
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After searching the web for a week, I admit that this is indeed the ultimate no-start diagnosis thread for M42.
Cobra Jet, my 91 318i has the same problem as you had. I won't start last Monday morning and I have been doing all the diagnosis with no luck.
1. The starter cranks at normal speed.
2. There is spark when I turned on the ignition, yellow spark, though.
3. The fuel pump works when I jump-wired the #30 and #87 of the fuel pump relay socket. I could hear the sound of fuel being injected into the intake manifold.
4. The fuel pump replay functions well. I tested it with multimeter
5. The Crankshaft Position Sensor has a resistance of 525 ohms, in the correct range, and socket connection looks clean.
6. I even pull out the DME, took off the alumnium shell and check the circuit board carefully, there is no water damage, no corrosion, not even dust there. Everything looks shiny and good.
7. After the last failed start, I put my nose close to the tail pipe and could smell gas easily.
6-month ago the car failed to start for the 1st time in the 7 yrs I have it. My mechanic replaced the fuel pump and it have been running well since then until last Monday.
ak96ss, RED IS 91, Cobra Jet and all the experts on this board, could you help? Thanks
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I forgot to mention that:
8. The check-engine light and all other lights are on, so I assume there is not fusible link issue.
9. The DME return code of 1444, which means no fault.
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have you pulled your plugs to see if they are wet with gas ?
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Good point. It is raining outside. Will pull the plugs to check if the rain stops tomorrow after work. I will let you know. Thanks.
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Good point. It is raining outside. Will pull the plugs to check if the rain stops tomorrow after work. I will let you know. Thanks.
Make sure you crank it over some before you pull the plugs.
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Make sure you crank it over some before you pull the plugs.
The rain finally stopped. But there wasn't much daylight left after I got home.
The original plan was to pull the plugs, check their condition; then put them back and crank it over and then check again. But it was just getting dark outside as I was pulling the plugs, so I decided to leave the 2nd part (crank and check) for tomorrow.
The plugs (Bosch Platinum +4, 3yr old) came out moist and with gas smell. There was also strong gas smell coming out of the plug holes. The electrodes look like in normal condition with some carbon deposits(a few carbon particles like the size of small ant). There is some liquid residue on the threads looking like water condensation? With a LED light torch I could see the piston tops, they seem moist (not wet) and covered with a thin and smooth coat of carbon deposit.
Now I remember that I actually rolled the car back and forth for a few feets on the driveway on 5/4, the day before the start failure (to find a solid jacking ground to check the brake pads); so the engine ran for about 10 secs each time.
If the engine was flooded, how long does it take for the cylinder to dry up by itself? I just left the plug holes open and hope all liquids will evaporate overnight. Will crank it over and check again tomorrow.
Thanks.
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I found this article very helpful .
Scroll down until you get to the no start check section.
http://www.bavauto.com/newsletter/2007_n407_newsletter.pdf
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UPDATE:
After a very kind M42 Member REDIS91 sent me a used CPS to try out, I can HAPPILY say the car STARTED! :D
When I received the borrowed CPS sensor, before installing it, I spec'd it out using my multimeter and it read a solid 524 ohms and I did this merely for comparison sakes against my original CPS.
As I previously stated above, when I tested my CPS IN the vehicle, I was getting a reading of 1180+ohms (the multimeter kept ticking off digits slowly). When I completely removed the original CPS sensor from my vehicle and re-tested it, it abruptly read 700ohms, then excelled to 1400+ ohms and kept going upward from there. I also visibly looked over the outer casing and found a very small crack at the "head" (or probe) end of the CPS. This very tiny crack was right at the junction where the wires go into the CPS head. After installing the used/borrowed CPS from REDIS91, the car started w/o issues.
I am still minutely puzzled as to why the DME never picked up a fault code for a faulty or non-functioning CPS sensor. When I had my prior 95 M3, the CPS died on it too, however, the E36 DME did register the correct fault code for the failed sensor. The only thing I can think of is the E36 DME is far more advanced and sensitive to picking up such issues than the E30 DME. The other thing I was also thinking was since the CPS was dead and was not able to register a spark, maybe that is why my 318ic's DME was not picking up the fault code, since it was not registering back a spark to the DME...??
I am greatly thankful for the "loaner" CPS, as this definitely helped to 100% confirm without a doubt that the CPS was the problem. Even though I did all of the testing as outlined in this thread and I had also used the BAVAuto newsletter as supplied above by REDIS91, I was still not 100% positive the non-start was the CPS sensor due to not seeing the fault code for it from the DME. Many of you were correct about the possibility of the CPS being bad and I want to thank EVERYONE who helped out in this thread!!!
I have a brand new CPS on order and coming from bimmerparts - thanks to Chris @ bimmerparts.
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BONUS:
I have never seen it done by anyone and since my original CPS was "dead", I figured I would dissect it. Here are my observations below (I will update this thread and pictures of the dissected CPS will be posted at a later date):
1) entire CPS sensor is vacuum molded in a black casing which protects the internal wiring. All of the internal wires go from the plug to the head.
2) outer black casing between plug & head is cut away to reveal a clear cellophane layer
3) below the clear cellophane layer, there is a very fine multi-stranded mesh wire that conforms and surrounds the next layer of material. This multi-stranded layer of fine wire is exactly like that found in a coaxial cable.
4) below the very fine multi-stranded mesh wire, there is a foil layer
5) below the foil layer, there are (2) wires - 1 black and 1 yellow. Intertwined in & out of those wires are (2) smaller, very thin black wires, but these wires do not have any copper centers. Looking online to determine what type of wires these could *possibly be*, I found that these might be Carbon Suppression Conductors. A carbon suppression conductor consists of a substrate of fiberglass and/or Kevlar over which high-resistance conductive latex or silicone is coated, and functions by reducing spark current (by resistance) to provide suppression. This is the same type of wire or material found in spark plug wires and other types of sensors. If those 2 smaller wires are not carbon suppression conductors I don't know what else they could be, or what purpose they serve.
6) at the plug end, the plug is molded & encased in black plastic. Inside of the plug there are (3) metal tabs. These tabs are the same tabs as seen at the open end of the plug of which you would probe for resistance. Tab 1 had a black wire soldered to it, Tab 2 had a yellow wire soldered to it and Tab 3 had the fine multi-stranded wire soldered to it.
7) The head or probe end of the CPS is encased by a thin metal layer that resembles a "can". This part of the CPS when operational "reads" the teeth on the crank as the crank is spinning and relays the info back to the proper relays & DME for spark & fuel. The metal can is thin and can be easily dented if hit or dropped. The head of the CPS is also magnetic, as I was able to pick up lightweight tools and other smaller metal objects with it. Once the metal can is cut away, it reveals the core of the sensor. The center of the core contains the magnet. The first outer layer of the core is an off white fabric. Under this fabric there is very thin brass wiring that is multi layered and wrapped numerous times around the core. The base of the core (where the wires are inserted to it) is black and is sealed w/ 2 rubber o-rings.
~~~~~~~~~~~
Neat huh?
Now, based on my observations and findings with the CPS dissection, IMO, there are (2) possible internal failure points:
1) The second layer under the outer casing is the fine multi-stranded coaxial wire. This wire if breached or if any single strands are broken can render the CPS inoperable OR you may get incorrect resistance readings above or below the correct specs for this sensor. Based on the fact that most 318's that are still on the road, some still retain the original CPS sensor. This sensor and it's materials due being 18-20yrs old and most having 80-100k+ on them are susceptible to underhood temp cycles and weather conditions which can and do make the outer casing very hard & brittle. IF this casing is damaged during an R&R process of any components around, near it or by dealing with the sensor directly or IF the casing is bent in a way it was not intended, there is the possibility of breaking or damaging the internal fine multi-stranded coaxial wiring. Any such break in this wire will damage the sensor. Remember, if ORIGINAL, they are OLD and can be easily damaged, so be careful when R&Ring.
2) IF the (2) small black wires found in the main wire casing are carbon suppression conductors, these can fail. These type of wires are cheap to make, they are found in multiple brands of spark plug wires and other types of sensors. These wires do their job extremely well while the conductor lasts. The conductor can fail (just as spark plug wires do) and this too will render the sensor either inoperable or show varying resistance when tested. Spark plug wires are limited life service parts depending on age, mileage accumulation and underhood temperature cycling conditions.
Based on my findings with the resistance/ohms readings of my original CPS and the dissection, it's safe to say that a CPS sensor is a limited lifetime part that CAN FAIL without warning and should be replaced based on age/wear/resistance readings.
Hopefully this thread is and will be helpful to others that are experiencing non-start issues, as there are MANY test methods covered, outlined and performed in this thread which will be beneficial to the "do it yourself" mechanic.
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I found this article very helpful .
Scroll down until you get to the no start check section.
http://www.bavauto.com/newsletter/2007_n407_newsletter.pdf
I am glad that Cobra Jet fixed his car.
This is the testing I did today:
1. All plugs were wet with gas after crank-over
2. All plugs have sparks
3. The engine did not start.
Based on what I read from all sorts of online posts, If there is spark and the fuel pump runs, the CPS should be working, right?
If there is fuel, spark and cranking, why didn't it start?!
The only things I could imagine are a broken timing chain(causing no-compression) or faulty ECU. But:
1. I have never heard any rattle noise indicating a failing or broken chain before and after the engine failed to start.
2. If the ECU is intact, shiny without loose joints and burnt components, can it be faulty while returning "1444" code and operating the relays and fire the sparks? Is there a simple way to test if the ECU is faulty?
I am totally puzzled. Really want to save this E30 but somewhat frustrated.
Thanks
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The DME is apparently working, because if you get or see the check engine light come on when turning the car on - OR you are able to extract any codes from it, it's working.
Have you tested the resistance values for the CPS sensor and the cam sensor? If you have not tested for these values, I would definitely get a multimeter and ohm test each of those sensors to see if they are within spec.
In the event I may have missed how you determined spark - did you do the method I did by pulling 1 spark plug wire off, inserting a plug into it, grounding it to the engine or chassis and having someone crank over the engine?
Try and test out that FPR - let's see what reading you get from it too.
Hmmm..... have you tested your ICV valve??? I'm asking this because I also had another prior non-start that had occured a few weeks before this last non-start issue due to the ICV valve not functioning... Quick test for ya - turn the key to the ON position, then put your hand on the ICV valve... The valve if working SHOULD be humming or "buzzing" - you can feel it and if close enough you can also hear it. If you do not hear ANY hum or don't feel any buzz - it's not operating. If not operating, you'll never get the car started either... Take the ICV off, clean it out, tap it a few times on the outer casing, reinstall and see if you get it to come back to life... About 90% of the time after a good cleaning and tapping, they come back. The internals get jammed up w/ carbon which prevents the spring/plunger mechanism from operating 100% and will either not allow any air into the intake or too much air... TRY IT (if you have not already)...
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From the tests you have performed, seems like the Crank ps is fine (getting fuel). I agree with Cobra Jet on the ICV. maybe a little more info on how the car ran before the no-start issue!? running rough? idle's weird? lack of power?
Maybe you have a bad engine ground ( I beleive it's located near the A/C compressor bracket, really not sure though)
if you have a compression tester, might be a good idea to check for that.
factory values: 220psi
good luck!
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The DME is apparently working, because if you get or see the check engine light come on when turning the car on - OR you are able to extract any codes from it, it's working.
Have you tested the resistance values for the CPS sensor and the cam sensor? If you have not tested for these values, I would definitely get a multimeter and ohm test each of those sensors to see if they are within spec.
In the event I may have missed how you determined spark - did you do the method I did by pulling 1 spark plug wire off, inserting a plug into it, grounding it to the engine or chassis and having someone crank over the engine?
Try and test out that FPR - let's see what reading you get from it too.
Hmmm..... have you tested your ICV valve??? I'm asking this because I also had another prior non-start that had occured a few weeks before this last non-start issue due to the ICV valve not functioning... Quick test for ya - turn the key to the ON position, then put your hand on the ICV valve... The valve if working SHOULD be humming or "buzzing" - you can feel it and if close enough you can also hear it. If you do not hear ANY hum or don't feel any buzz - it's not operating. If not operating, you'll never get the car started either... Take the ICV off, clean it out, tap it a few times on the outer casing, reinstall and see if you get it to come back to life... About 90% of the time after a good cleaning and tapping, they come back. The internals get jammed up w/ carbon which prevents the spring/plunger mechanism from operating 100% and will either not allow any air into the intake or too much air... TRY IT (if you have not already)...
Update today:
1. There is no ohm reading b/w terminal 1&2 of the camshaft sensor. I tried both a digital and a analog meter. So I bet it's faulty.
2. The crankshaft sensor reads 520 ohms in previous test.
3. The ICV did buzz but very faint as I can barely felt it with fingers on. I took out the ICV and checked inside. It looks clean without much deposit or soot. I am not sure how to test it, though.
4. After camshaft sensor and the ICV disconnected, I checked the DME code using the "pedal pump" method, and still getting 1444! Shouldn't the DME return some faulty code? I am saying b/c last time when the MAF connector was loose about a year ago, the DME did return the correct doe.
5. I did use your method to check the sparks. after that I even pulled out every one of the plugs from head cover to check. They all fires normally.
6, The FPR is not easily accessable so I have not tested it. But for sure the pump was working and I was getting gas in the cylinders.
Would a bad camshaft sensor cause no-start situation? I am not sure what the sensor does and if it must be replaced.
One more thing, when I pulled a rubber hose (don't know what it's called but it's close to the front, or the radiator side of the engine, one end is connected to the head cover, the other end to another hose with "T" connector, under the intake manifold), some clear water (not a lot) came out of it. The inside of the hose was covered with some yellowish foam like stuff. Should there be water in the hose?
B318M42W, I used the car for daily commute (less that 5 miles each way) and it was running normal. The idle sometimes went rough slightly at stops for a few seconds, but not often. While testing the sparks, I grounded the plugs to the cylinder head cover and spark fired normally, so I guess the engine ground is good.
Thanks.
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so if i get your situation right... you DO have spark and you DO have gas. based on the fire triangle, air is the only thing left... I,m not a mechanic or anything, so i might be waaayyy off...
here's what i'm thinking: either some of your injectors are stuck open (too rich to burn), or maybe your engine isn't breathing right. My 318 had a little idle issue on start-up, turned out that the MAF was starting to go bad. (and the DME didn't give me any codes...) maybe take a look at your MAF, just to rule it out? and also check your air filter? easy stuff, shouldn't be too long.
good luck
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Cobra Jet--thanks for the detailed analysis. It's good that members take the trouble to follow up and even do a sensor dissection!
In the dissection, the outer layer serves as a shield for the internal signal wires. It's typically grounded at the connector end, and left unattached (floating) at the sensor end.
I believe the thin intertwined wires are used to control inductance in the two core wires, especially the way you described them as being woven. Inductance can distort a signal that varies in frequency (rpm). The same principles are used in high-end audio connectors.
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so if i get your situation right... you DO have spark and you DO have gas. based on the fire triangle, air is the only thing left... I,m not a mechanic or anything, so i might be waaayyy off...
here's what i'm thinking: either some of your injectors are stuck open (too rich to burn), or maybe your engine isn't breathing right. My 318 had a little idle issue on start-up, turned out that the MAF was starting to go bad. (and the DME didn't give me any codes...) maybe take a look at your MAF, just to rule it out? and also check your air filter? easy stuff, shouldn't be too long.
good luck
Yes, he's good w/ fuel, spark & operatinal DME, so the fuel pump, DME, relays for fuel pump & DME & CPS can be ruled out at this point.
As you mentioned, the engine getting or needing air is important. The ICV and the AFM control the air intake for the engine. I would thoroughly clean out the ICV, because just by looking into open ends of it, they normally won't look "dirty" from that vantage point. The problematic area is within the actual cylinder, where you can't see anything. The internal parts of the cylinder contain a spring & plunger mechanism, which when powered up opens and closes the ICV valve and this regulates the air going into the intake/engine. If the ICV cannot regulate the air, you will experience the idle flucations, high idle, low idle, etc. In the event that the internals of the ICV are stuck, the car will be hard to start and/or you won't be able to start the car at all. As soon as the key is turned to the "on" position, the ICV powers up and will always have a slight "buzz" to it so you'll know at least it is getting power.
When my ICV was acting up, I could not start the car and when touching the ICV or listening, the ICV was not operational at all - no buzzing. When I tested the resistance on it (ohms), it was out of spec too. So, I removed it, soaked the internals w/ carb cleaner (brake cleaner will work too) and after it dried out, I also shot WD40 inside to lubricate the plunger/spring mechanism. I then tapped around the entire outer casing w/ a hammer hard enough to dislodge the internals but not so hard to damage the casing. After performing those steps, I then retested the resistance and it was very close to spec, so I reinstalled the ICV. The car started right up after the cleaning and drove fine.
Now, the AFM also controls air intake and if the AFM is dirty, it too will either be completely non-functional OR partially functional. I did not have to clean mine, as when I removed it and looked everything over, it was really clean to begin with as M42 Member bmwpower had cleaned it before I bought the car from him. There are some threads on this site that discuss cleaning the AFM, I'd search for those threads if you do want to clean it.
As for the camshaft sensor - the camshaft sensor is relays info back to the DME for sequential fuel injection and knock control.
Here's a good thread for you! Another M42 Member started this thread about finding a faulty camshaft sensor. In it, he also states his CMP sensor read "0" when the resistance spec should be 1250 ohms (do read the thread, because it does have valuable info about that sensor):
http://www.m42club.com/forums/showthread.php?t=5376&highlight=camshaft+sensor
I think you're almost there to getting your M42 back on the road!
:)
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Ok. The ICV reads about 8 ohms on multimeter, in the correct range. The valve did activate when charged with 12Volt, but there is some black soot in there I will clean out.
The air filter is fine. The temperature sensor in the AFM is clean and the duct is clean, too. There are 5 labeled pins on the connector but can some one tell me which pins I should check with multimeter and what is the correct ohm value?
With the ICV and AFM off, I tried to crank over. Still won't start; but for a few cranks it felt like the engine was almost trying to start for a split second but couldn't. After that, the DME did return the correct faulty code 1262 (ICV problem b/c I disconnected it)
If the no-start was due to no air getting in, why won't it start with open air ducts?
Cobra Jet, if the camshaft sensor helps the DME on sequential fuel injection control, could a faulty cam sensor mess up the fuel injection or spark timing and cause no-start? I am asking b/c I read from the thread (
http://www.m42club.com/forums/showth...amshaft+sensor) that engine should run with bad cam sensor. (I posted the question there, too)
Thank you folks for giving lots of help on this. I am going to get some carb cleaner now.
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If you tested your camshaft position sensor and it was faulty why haven't you replaced it ? :confused:
These sensors all work together through the computer.
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If you tested your camshaft position sensor and it was faulty why haven't you replaced it ? :confused:
These sensors all work together through the computer.
I didn't know the cam sensor was bad until last Thurs. I did google search and learned that a faulty cam sensor (also called cylinder identification sensor) cause some issues, but was not convinced that a bad one would prevent an engine from starting. See this article: http://www.diagnostic-assistance.co.uk/cid.htm
Besides, I have been as puzzled with my DME code as Cobra Jet with his b/c the it never returned a faulty code 1244 (for cam sensor problem)1444 code, even with the cam sensor disconnected!
So I am not sure the cam sensor is the culprit for the no-start problem.
That said, I am placing an order for a new one and hope it will solve the problem. Will keep you updated when I receive it.
The ICV is now cleaned and functions well. Thanks to Cobra Jet's advice.
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If the cam sensor is faulty the computer won't be able to tell the injectors when to squirt fuel into the cylinder.
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thanks to everyone for documenting these non-start issues, testing, and remedies...I unfortunately too am having some very similar issues...intermittent starting/running for a couple days/no sound from the fuel pump/etc...I too will be going through the same steps/tests documented here, but had a couple specific questions....
One, where exactly is the crankshaft position sensor located? Any pictures would be greatly helpful (I'm a visual person)...also, where is the camshaft position sensor located?...
Regarding changing the fuel pump (if it gets to that)...does all the fuel need to be out of the tank to do this or can it be changed with fuel in the tank? (I have about a 1/2 tank currently)...
Lastly, in the fusebox, there are (oh about 6) 1 inch by 1 inch orange blocks...very stupid question but what are those? Are they related to any issues with the fuel pump...I had thought one of those might be the fuel pump relay, but after seeing the photo above, I see that that is not the case...I now know where that is at and will look into that tonight...at any rate, I'd be grateful for any insight.
Jay
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One, where exactly is the crankshaft position sensor located? Any pictures would be greatly helpful (I'm a visual person)...also, where is the camshaft position sensor located?...
A) CPS (crank sensor) - if looking at & standing in front of the engine, the CPS is located at the very bottom to the LEFT of the crank. The crank balancer is the last "pulley" at the bottom of the engine and has teeth on it (the CPS reads the teeth). The CPS is secured to the engine via a small metal bracket. You can see the CPS much better if you are looking under the vehicle (if it's on ramps or a lift). It's hard to see from the top side.
B) CMP (cam sensor) - if looking at & standing in front of the engine, the CMP is located on the front of the head, right above and slightly to the left of the thermostat housing (above water pump). The sensor is secured to the head via a small Torx screw. You can visibly see this sensor when the hood is open.
CPS has a long black wire and is the bottom plug on the black junction box found under the intake on the driver's side of the engine. CMS has a short black wire and will be the top plug on the same black junction box on the driver's side of the engine.
Regarding changing the fuel pump (if it gets to that)...does all the fuel need to be out of the tank to do this or can it be changed with fuel in the tank? (I have about a 1/2 tank currently)...
No, the fuel tank does not need to be emptied at all.
Remove lower rear seat cushion. On the passenger side (if standing in front of the vehicle), the fuel pump access panel will be on your LEFT after removing lower rear seat cushion. Remove the (4) Phillips head screws from the metal access cover. Remove metal access panel cover. Loosen the clamps holding the section of rubber fuel line that goes from the metal body fuel line to the top of the fuel pump (it's only a single rubber hose and easy to identify). Pull rubber line off fuel pump outlet after loosening clamps. Unplug electrical fuel pump connector from fuel pump. Unplug fuel tank level sender connector from level sensor. Grasp the fuel pump and turn it (counterclockwise I believe). This will release the fuel pump from the top of the tank. Slowly pull the fuel pump out of the tank. Be careful when removing the fuel pump from the tank, as there is a black rubber O-ring that is between it and the top of the tank - DON'T LOOSE THE O-RING, you will need to use it again when reinstalling the pump. Install is the reverse of removal.
Lastly, in the fusebox, there are (oh about 6) 1 inch by 1 inch orange blocks...very stupid question but what are those? Are they related to any issues with the fuel pump...I had thought one of those might be the fuel pump relay, but after seeing the photo above, I see that that is not the case... Jay
No, they (orange relays) are not related to the fuel pump in that fuse box. The only fuse you want to be concerned w/ in that engine bay fuse box will be Fuse location # 11 - this is the fuel pump fuse. The orange relays in that sealed fuse box are for the headlights, high beams, etc etc etc...
The actual RELAYS you do need to be concerned w/ are found underneath of the black plastic covering located on the firewall in the engine bay. This will be located directly below the windshield wipers at the very top of the firewall in the engine bay. You just pull the cover carefully and it will come completely off (there are clips on the far right and far left that you have to unfasten underneath of the cover to let it come loose). Once that cover is removed, you will see the (3) relays on the DRIVER'S side of the firewall (DME relay, Fuel Pump relay & the O2 relay). These are the problematic relays on some vehicles.
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If you have an "intermittent" problem, I would definitely start with ohming out the CPS - the CPS can or will be intermittent when is starts to fail or it can (and will) just fail completely.
If a fuse fails, it fails completely and is dead (blown), there are no intermittent signs prior to a fuse failure, it just dies instantly and anything linked to it will be inoperable as well. A relay on the other hand *could* be an intermittent problem if the relay contacts inside are sticking. I've heard of other people taking apart relays and cleaning them w/ Eletrical Contact cleaner, but I have never tried to do this myself.
Hopefully this thread and the above will help you out. Do post back any other questions and/or results!
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Thanks so much for your assistance/response...I will report back after I've gone through the tests...
Jay
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CAREFUL
remember,If your changing the fuel pump be very careful about sparks and ventilation (fumes)while removing.
Have both doors open ,sunroof too if you have one .have a fire extinguisher near by.
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If the cam sensor is faulty the computer won't be able to tell the injectors when to squirt fuel into the cylinder.
I replaced the cam position sensor yesterday. The bad news is that the engine still won't start. So let me recap:
1. There is spark
2. Fuel pump relay and fuel pump works and the engine should be getting fuel. I could smell gas in the tail pipe after crank-overs
3. According to Cobra Jet, if there is spark the CPS and DME should be working. The CPS did read a resistance in the spec (could a faulty CPS still fire up the sparks but mess up the spark/injector timing?)
4. The ICV should be working and I cleaned it.
So why the engine cranks normally but won't start? Did I miss anything?
I am going to follow B318M42W's word and test the compression next. But my gut feeling tells me the problem lies somewhere else. I am saying so b/c the car was operating normally the day before the no-start. Can all 4 pistons or the valves be damaged all at once without warning signs?
This must be among the most mystorious no-start problems. Thanks to you guys for stay with me and I still need advice.
BTW, Looks like there is continued interest on this topic. Colo318IS, good luck.
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318i91 -
How old are or how many miles are on your timing components or do you know if any of the timing components have ever been replaced? The reason I am asking is another type of non-start issue that could occur IF you do have spark is that the timing components are no longer within spec or alignment. If somehow the timing chain skipped, the chain broke or the timing sprockets have become misaligned, then the engine timing will be affected which could create non-start issues.
If you are indeed getting spark then the car should fire up providing you are also getting fuel AND air to the engine... You have said you are getting spark for sure, so it would seem that your ignition coils are productive and the CPS may be functioning properly (or at least within spec). Also, from what I was told in this very thread, if you see the check engine light when you turn the key to the "on" position and are able to get it into the code extraction mode, then the DME Relay is good, the DME is getting power and supposedly is working. I suppose a DME could have other issues which may affect it's internal data operations, but I don't know how to diagnose DME internal failures.
What was your CPS readings? Did you take a reading w/ the CPS removed from the car and also take a reading w/ it installed?
Just curious too - when you removed the old CMP, what was the reading w/ it removed from the car? If you still have it, see if it still tested out at "0" as it did when you initially tested it.
What is puzzling is you are saying you have spark... Is the AFM and ICV within spec too (both components regulate air into the engine)?
If the fuel pump is working is fuel definitely getting to the injectors is each injector firing or spraying fuel as well? Have you tested the fuel pressure?
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thanks Red IS 91 for the cautionary notes...yes, definitely will be careful when messing around with the fuel pump (I think I've read and re-read this thread I dunno how many times and probably a couple more times:))...good luck to you to 318i91 as well, sorry to hear you're still havin issues...I'm hopin to get some time this weekend in to work on it...I'll stay in touch!
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318i91 -
How old are or how many miles are on your timing components or do you know if any of the timing components have ever been replaced? The reason I am asking is another type of non-start issue that could occur IF you do have spark is that the timing components are no longer within spec or alignment. If somehow the timing chain skipped, the chain broke or the timing sprockets have become misaligned, then the engine timing will be affected which could create non-start issues.
155K on the engine and I don't think the timing chain has ever been replaced. I wish the timing chain did not skip b/c I may lack the skills and equipment to fix it.
- If you are indeed getting spark then the car should fire up providing you are also getting fuel AND air to the engine... You have said you are getting spark for sure, so it would seem that your ignition coils are productive and the CPS may be functioning properly (or at least within spec). Also, from what I was told in this very thread, if you see the check engine light when you turn the key to the "on" position and are able to get it into the code extraction mode, then the DME Relay is good, the DME is getting power and supposedly is working. I suppose a DME could have other issues which may affect it's internal data operations, but I don't know how to diagnose DME internal failures.
I am crossing my fingers on that.
What was your CPS readings? Did you take a reading w/ the CPS removed from the car and also take a reading w/ it installed?
Just curious too - when you removed the old CMP, what was the reading w/ it removed from the car? If you still have it, see if it still tested out at "0" as it did when you initially tested it.
The CPS has 520-ohm resistance. I did not remove it as it's not easy to access. The OLD cam sensor didn't have a reading when it was in. Then I removed it and actually could read 1260 ohms which is in spec. After careful check, I found a crack right where the cable going in the sensor head. I think the the cable has poor connection at the crack so the sensor did not read, but once removed the cable could flex to better connection and read ohms. The NEW cam sensor reads 1420 ohms, really at or off the upper boundary of the spec.
What is puzzling is you are saying you have spark... Is the AFM and ICV within spec too (both components regulate air into the engine)?
When I took it out of the car, The ICV initially read 8 ohm which was in spec. After soaking it in cab-cleaner for 30mins(not sure If I damaged the coil by doing this), it read 2-3 ohms but the valve still operated when 12V was applied from a power adapter. Now, the ICV's does NOT move when I put it back to the car and turn the ignition to "ON" position. I could hear very faint buzzing only with ears directly on it. but the metal valve does not move at all (looking from the openning). The cable to the ICV valve does have 12V reading on it.
There are 5 pins in the AFM. Which pins should I check?
If the fuel pump is working is fuel definitely getting to the injectors is each injector firing or spraying fuel as well? Have you tested the fuel pressure?
How do you check if the injectors are working?
Going to buy a compression tester now and check compression tomorrow after work.
Thanks
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The good news is I may just found the culprit. The bad news is that the problem may be serious.
The compression in the 4 cylinders reads:
cylinder 1: 40psi
cylinder 2: 75psi
cylinder 3: 32psi
cylinder 4: 35psi
Then I did a "wet" compression test with cylinder 4. With some 10w-30 oil to seal the rings, it read 80psi.
That tells me that I may have:
worn piston ring and/or cylinder wall, or
worn piston ring, cylinder wall and valves
I remember reading an article that for an engine to start there need to be at least 65psi pressure in cylinders. So low compression caused the no-start issue?
I would think that a worn engine would develop chronically aggravating driveability issues long before it fails. Yes, the car did not accelerate quick. but it constantly gave 25-30 GPM fuel efficiency. Shouldn't a worn engine turn much worse MPG? Besides, the engine just passed 155K mils mark. I have heard a lot of bimmers with 200K+ miles on them and still running great. So is it normal for this one to be so worn
So the puzzle is why the engine ran well on Saturday and suddenly stopped working next Monday? One possible explanation may lies on what happened on Saturday. I was checking the brake pads and had to roll the car up and down the driveway a couple of times trying to find a good jacking base. Each time the engine ran for a few seconds. In doing so unburnt fuel might flooded
the piston and washed off the oil. As I mentioned above, Cylinder 4 reads 35psi in "dry" compression test and 80psi in "wet" test. Assuming it's true that the engine need at lease 65psi to fire up, the oil being washed away removed the seal b/w the rings and cylinder wall and reduced the compression below 65psi threashold thus cause the engine not to start, even though everything else works normal.
But every time I crank the engine, Shouldn't oil be pumped to the piston rings and cylinder walls and seal where they contact, thus restore compression? Anyone have a good explanation for this?
Another thought is that if the above is exactly what happened, may be I could revive the engine by changing to thicker oil like 20w-50 and feed a tea spoon of oil through each spark plug hole. The risk is that every time I let the engine sit for a couple of days, I may not start the next morning.
Anyone have experience fixing a low compression problem? Does that require special tools/equipment, skills and a lot of hours? How much could it cost to have a repair shop open the engine and change rings, pistons or both?
What to do now? Any suggestion is welcome here. I am still not ready to give up.
Cobra Jet, I saw you started another popular thread on #87 gas. I have used #89 for the past 3 years. But after going through these compression diagnostics, I guess an older engine with lower compression can probably use #87 safely simply b/c the low compression won't detonate the lower-oct gas. Do you agree?
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I find it hard to believe that one day it runs good then the next day won't start with no compression.
How did you perform the compression test ?
Are you sure your compression tester o ring was good ? I would try another tester to be on the safe side .
It just doesn't add up ..............................I may be wrong though:confused:
good luck
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I find it hard to believe that one day it runs good then the next day won't start with no compression.
How did you perform the compression test ?
Are you sure your compression tester o ring was good ? I would try another tester to be on the safe side .
It just doesn't add up ..............................I may be wrong though:confused:
good luck
RED IS 91 -
I tested the compression with a brand-new compression tester from Advanceautoparts for $25. The tester come with an extension hose so I can reach down the deep plug hole. With all plugs, main relay and fuel pump relay out, and the tester fitting screwed in (o-rings seated well at fitting-to-hose connection), my neigbour cranked over the engine while I watched the tester dial until the pressure reading stables, after about 5-6 revs.
You raised a good question: How did the engine run ( I forgot to mention that it had never burned oil) with such low compressions. As I mentioned in the last post. The "wet" compression test raised the compression from 35psi to 80psi, right above the minimum ignition compression of 65-70psi. Maybe the car kept running just b/c I never let it sat off road for too long so the oil helped sealing the worn piston rings by pure luck for so long? But it still doesn't explain why it didn't burn oil with all the worn rings. I plan to put some thicker oil in each cylinder tomorrow and see if it make some difference.
Another possibility: maybe a skipped timing chain (Just like Cobra Jet suspected) messed up with valve timing so the valves are partially open in the compression stroke so the pressure is low?
Have anyone heard of M42 very-low-compression issue before and know how to diagnose/fix it? I am all ears.
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No one can offer some ideas?
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you must check what is wrong with the compression...It is too low...i do not believe that you have a problem with the pistons or the piston ring , you should check for a crack in the cylinder head...There is no way the car worked fine and imidiatly droped pressure from the pistons...check your timing , remove the valve cover , and read from a manual about timing and where all the parts should be , check it and see if you have any timing issues...
edit : if there is wrong timing , the valves would be open and no compression would be possible....
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you must check what is wrong with the compression...It is too low...i do not believe that you have a problem with the pistons or the piston ring , you should check for a crack in the cylinder head...There is no way the car worked fine and imidiatly droped pressure from the pistons...check your timing , remove the valve cover , and read from a manual about timing and where all the parts should be , check it and see if you have any timing issues...
edit : if there is wrong timing , the valves would be open and no compression would be possible....
Still googling on similar issues. One guy had a low-compression problem b/c no spark in two cylinders and the gas washed off oil sealing the rings. I may also have blown gasket.
Severe T-storm with wind gusting 60+mph this afternoon. my cherry tree in the yard was blown over. big mess.... Strong storm continues Thu and Fri...
Will open the hood after that.
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We had a similar issue yesterday with a 91 318is.
Fuel pump died (whirring and whining and car eventually would not start). Swapped a new pump in - car won't start, cranks, but no start. Fond this thread which helped immensely.
the pump would not come on, even when starting the car. There was voltage at the pump connection when cranking though. We though maybe we got a bad pump. Pulled it and checked the wires just to be sure.
We swapped all relays from another car that was running, no luck.
We ohmed the crank/cam shaft sensor. Crank was 525 (same as our running car) and cam was 1000 (about 200 to low).
Next I jumpered the fuel pump relay and immediately heard the pump fire up, and could here fuel coming into the rail.
Went to start the car, and it started, but ran really rough.
I think the bit of fuel from jumpering the pump got it started, but not sure.
Now I swapped the cam shaft sensor, and it started up and smoothed out. Swapped in a new o2 after that and took her out. Runs great and idles great. Hopefully we got it all figured out.
Good luck to anyone else that finds this thread (it should be stickied, really great explanation of how the entire startup works).
Thanks!
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Status update on my M42 Non-start issue…
First, sorry for the delay, I accepted a new job and with packing and the move, had to table working on the car for a few weeks…
I went through all the tests above (Testing pump, FRP, CPS, Cam PS, etc) and came to the conclusion the pump went out. I had removed it and jumped it from the battery and got nothing. I ordered a new one and put it in last weekend, but now a new issue has cropped up...
After installing the new pump, I tried to start it several times. At first it started, idled for about 45 sec then started to show signs of what it did when the original pump went out--that is, it sputtered and even when pushing the gas down it wouldn't go over 800 rpm then finally died. On several repeat attempts over a couple days, it would sound like it was just about to start right when I turned the key, but then would just crank.
One thing I noticed that I thought was strange was the new pump was not turning on with the key on, engine off. It would only turn on as I was trying to start the car. Any thoughts?...isn't the pump supposed to turn on when the key is turned on? My thought was that's why it's not starting b/c the pump isn't priming the system thus not gettin enough fuel to the engine to turn over. It would also turn on if you jump it from the battery. Voltage is good at the harness.
The other thought was is this a fuel mixture issue which is separate from the pump issue?
Thanks for any insight...
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did you change the fuel filter recently ? You should check the fuel pressure at the pump .You should have 42-43 psi.
It sounds like something is telling the fuel pump not to start :confused:
You could disconnect the line that goes into the fuel filter ,stick it in a jar and see if the pump will pump fuel when you turn the key to the "on" position.
Be careful doing this.If it does not then the pump is not getting a signal to start.
When you turn the key to the on position do you have 12 volts at the pump?
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Yes I did change the fuel filter prior to the new fuel pump. I haven't checked the fuel pressure but will.
I did actually disconnect the line into the jar...what happened was no fuel came out when the key was turned to on...fuel would only come out when either tryin to start the car or jumping the fuel pump. Also, there wasn't voltage at the pump when the key was turned on...only when you tried to start it would it read 12 volts...weird...so yeah somehow something is telling the pump not to start but other thought I had was that aside, when looking back at my starting the car when it did run...probably 98% of the time I put the key in and start it w/o giving the pump really any time to prime...started wondering if maybe it was a spark issue then? I did replace the plugs, but only tested a couple for spark so maybe a coil is bad?
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Colo - did you do the pedal stomp test to retreive any stored codes? If you did do this already, are you able to get any codes?
When you turn the key to "on", can you hear the fuel pump prime? You should be able to hear this audible priming instantly. Pull the rear seat cushion out and listen closely when you turn the key to on.
Also, make sure that when you installed the fuel pump connector back onto the fuel pump that you installed it properly, because IF the connector was reversed, the fuel pump will NOT pump fuel towards the engine, it will be pumping in "reverse" (basically not pumping it through the fuel lines to the engine)... check that connector to make sure it's making proper contact at the fuel pump, do the "wiggle test" when trying to start the car.
It sounds to me like the car only ran on the available fuel that was left in the lines, then died after there was no more fuel source.
What was your CPS results after testing it?
Another thing to check would be the ICV valve. Have you cleaned or checked your ICV valve? If the ICV is not operating 100%, you will experience hard cold starts, hard starts when hot and/or rough idle, stalling, etc. The ICV needs to be operating at nearly 100% in order for the engine to run or idle properly. If the ICV is not operating 100%, it's not allowing the proper air flow into the engine for idle or when driving, therefore the engine will experience irradic idle, the inability to run properly or it can or will stall out.
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fuel pump relay ?????
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The fuel pump doesn't prime when the key is in the on position. It turns on when the ECU detects that the engine is turning over via a signal from the crank position sensor. The noise you hear is probably your antenna motor activating when the key is in the on position.
There's a check valve in the fuel pump that prevents fuel drain-back so that the fuel line stays charged.
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When you turn the key to the on position you should hear the fuel pump relay click on .It is located on the fire wall ,drivers side (usa), behind the plastic cover.
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Another update on my end.
First again sorry for the delayed response, was out of town for a couple weeks...
OK...
Cobra Jet: I did do the pedal stomp a few times...it comes up 1444 (No fault)...
REDIS91: FPR is good, it does click on. CPS is good.
I think I'm getting closer to a culprit now, which I think is the ICV. I did check the connections on the fuel pump and they are good, but I decided to check the fuse again (I had checked the fuse long ago when I first encountered my no start). As you'll likely know and to my knowledge there are two main fuses for the fuel system (#10 & 11)...10 amongst other things is for the fuel gauge and 11 is for the pump)...I know there are several ways to check a good vs. bad fuse, but what I thought was helpful was to put in a known good fuse in 11 and put the fuse from 11 into the 10 slot...when i did that, got nothing on the fuel gauge telling me the fuse I had in the 11 slot was bad. So I replaced the 11 fuse.
The car fired right up and did what it did a few weeks ago when we replaced the fuel pump. It ran for about a minute, then couldn't maintain power and died. I then removed the ICV based on Cobra Jet's comments and other research, cleaned it with carb cleaner, tapped it, etc..reinstalled. Oh before I reinstalled, I checked it...Ohms read 9, which it's my understanding it should be 20, another sign the ICV is bad. It didn't start. I then started thinkin about the fuse again, so I checked it. Blown fuse. I put another one in, it fired right up, ran for a minute, died. checked the fuse. Blown again.
So just curious your thoughts on this...my current thought is the ICV is bad and too much fuel is getting into the engine...it's overloading the system and blowning a fuse which is shutting the pump off which is why it dies. Any thoughts?
As to the ICV...like I said, I did remove it and clean it, but don't know whether I did a good enough job on this or tapped it enough? I obviously didn't want to damage it, but did give it slightly more than a gentle tap, tap, taparoo. When I did tap it, I felt like I could feel a slight vibration as a sign it wasn't clogged anymore. Also, when I cleaned it with carb cleaner...not a ton of "gunk" came out? Is that normal. Thought about trying to clean it again before breakin down and ordering a whole new ICV. Lastly, after it is cleaned, should it read 20? I never did retest it after I cleaned it.
As always, thanks so much for your thoughts.
Jay
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If you remove the icv you can connect 12 volts to it and see if the little door inside moves when you connect the power.
It's not a good sign to be blowing fuses for the fuel pump .It should be a 15 amp fuse for that I believe.
I don't know how that relates to the icv??
also are you sure you hooked the hoses up correctly at the fuel pump??
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...well damn, thought this day would never come, but am happy to say I'm back in business! Just got back from a drive.
I did clean out the ICV, but it was functional and I don't think that was the issue...I started thinking that due to research I had read on rough idles/etc.
OK, I believe the issue was the connection on the pump (thank you to RedIS91 & Cobra Jet)...I did pull the cover off the pump and checked the connection, it was indeed not tight. It fired right up after that and idled normally. I have taken it out a few times and so far so good.
Thanks so much for everyone's help!
Jay
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Wooohoooo!!
Glad to hear it's running again Jay and that this thread helped you out with your non-start issues.
So, in the end, it was the actual plug that goes on the fuel pump? Was it corroded or just loose?
What I also did w/ my fuel pump plug was I had opened the hard plastic that surrounds the inner metal female connectors (it's easy to do, just use a small flat head screw driver and pry the two plastic pieces apart carefully). Once I had the metal female connectors in my hand, I used a pair of plyers and pinched each one ever so slightly. What this did was to close up each round opening on each connector just a little so that when reinstalling the main plug back onto the fuel pump connection, it would now "grip" and be more secure on the fuel pump than it was previously. You may want to consider doing that if yours was loose. Also, just remember which connector goes back into the plug when putting the plug back together - because if you reverse polarity, the pump won't pump fuel out of the tank... LOL (learned that from experience)... :)
Great to hear that you're now out & about! Best of luck!
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another happy ending, that's what we like to hear !:D
congratulations :)
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yes, mine was just loose, nor corroted, thanks for the tip, I will do that.
I dunno, it was a little bit of a blur when we put the new pump in and I honestly thought it was tight, but evidently not. Well one side benefit...prior to this issue, when I would start it, it would have a hard time maintaining idle until you drove it a mile or so...now after cleaning out the ICV..WOW, what a difference...idles like a champ.
Yes, very excited to be drivin it again! Thanks again...i hope one day to return the favor!
Jay
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Having a very similar issue, looking for some additional guidance.
I believe these could all 3 be related but not sure.
My fuel pump relay is having issues.
Has no ground, when I make a set of jumper wires I can make it work, yet when plugged in the Ground is lost. Is the ground routed to the computer (book states this) or elsewhere? I have an extra computer, tried it with no change in result so believe the ground must be else where.
Pump is only getting power when the key is in the START position, no initial2 sec power up and once key is to on position nothing, possibly due to the non start I am sure. But it should have the2 sec power up and it does not. What controls this, computer?
Last issue which may be the root of all this evil is (quite working on it when I found this) the Cam position sensor appears to be dead we cannot get it to read any ohms’, nothing tried all the combinations. What could this effect, all the above? Where is the best place to get a new one dealer or does someone else have them at a better price? BMA?
Thank you in advance.
Richard
Houston
A few e30's
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Camshaft position sensor should have 1250 +- ohms . If you don't have that then replace it and report back. Link below to sensor.
Check you crank position sensor also.
http://www.autohausaz.com/search/product.aspx?sid=ovw5r355z2n4ig550yoybp45&makeid=800003@BMW&modelid=1011249@318I&year=1991&cid=25@Ignition%20Parts&gid=7192@Camshaft%20Position/Reference%20Mark%20%20Sensor
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Crank sensor was okay, in the car, so I did not remove it. Cam sensor has been ordered. I will keep you informed, appreciate it.
Thanks RT
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good luck!
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Hi everyone, I am finding this thread very useful in my quest to get my car started again. Last Friday, like the other stories in this thread I went to town without a problem, but when a few hours had passed and it was time to leave I cranked and cranked and cranked some more and in the end had to tow the car home as it just would not fire up.
I have been using the information below to guide me, but I am getting some results that I need help interpreting, I hope the author or others can help! I'll put my comments/questions below in bold and some bright color so you can all see where I am having problems.
I concur, it may very well be the crank position sensor, but to confirm that you are in fact getting power to the pump, let's go over how the start circuit works for the fuel pump (as I understand it, anyway!).
Power comes from the junction block down the yellow line to the DME all the time, but the DME doesn't send it into the starting circuit until it senses that you have the key on. So, the blue, green, and red lines have power, but aren't doing anything with it yet.
I have verified that I have power to pin 26 of the DME(Yellow), and I've also verified that there is power at pin 86 and 30 of the MAIN relay as well as pin 30 of the FUEL relay. This is before turning on the key!
(http://lh5.ggpht.com/2006TopBanana/SA3XhzBQMrI/AAAAAAAADVY/zBRY2rCf3_U/s800/start1.jpg)
When you turn the key to the ON position, it grounds the green line at port 27 (Main Relay Control), causing the green line to have power all the way through the main relay via tabs 85 and 86.
Here's where the problem occurs for me, I can feel the MAIN relay switch close and power goes from pin 30 to 87, but I cannot see power at pin 85 of the MAIN relay???
(http://lh4.ggpht.com/2006TopBanana/SA3XijBQMsI/AAAAAAAADVg/uKC6lo3g0QU/s800/start2.jpg)
This energizes the coil and pulls the relay closed, sending power through the main relay from tab 30 to tab 87, and from there to (among other places) the fuel pump relay's tab 86. But the fuel pump relay's tab 85 is still not grounded, so power doesn't go through yet.
(http://lh6.ggpht.com/2006TopBanana/SA3XjDBQMtI/AAAAAAAADVo/wiEspi_6oe0/s800/start3.jpg)
The DME checks to make sure that the engine is rotating using the crank position sensor - when it sees that the engine is in fact moving, it grounds the fuel pump relay control at port 1, completing the blue circuit.
I have checked both the Crank position sensor and the cam position sensor, they read 550 and 1200 with my multimeter. I also have removed a spark plug, connected it to the wire and witnessed it sparking while the engine was being cranked. I understand that to confirm the CPS is working correctly, or?
(http://lh6.ggpht.com/2006TopBanana/SA3X4DBQMuI/AAAAAAAADVw/xogXcUzCXUA/s800/Start4.jpg)
Now that the blue circuit has power going through it, the fuel pump relay coil pulls in, energizing the red line and sending power through tabs 30 and 87 to fuse 11.
(http://lh4.ggpht.com/2006TopBanana/SA3YEjBQMvI/AAAAAAAADV4/XZVOXo-4-0M/s800/Start5.jpg)
Assuming fuse 11 is good, power goes to the fuel pump, and it starts pumping fuel.
If the crank position sensor is malfunctioning, the DME won't know that the engine is turning, so it won't turn on the fuel pump.
So, to systematically test and make sure that the circuits are working as they should, start with a fused jumper wire at the fuel pump relay. I actually use a switched, fused jumper, so I can turn it on and off from the engine area. For all of these tests, when I say 'ignition on' I mean in the RUN position, not the ACCESSORY position.
First, exchange fuse 11 with another fuse (same or lower amp rating, never higher). Just in case the fuse is bad, but still looks OK. It's rare, but it does happen. See if it will start. If not...
Remove the fuel pump relay. Insert one end of your jumper wire into the hole where tab 30 goes, and the other end into the hole where tab 87 goes. With the ignition on, the pump should start pumping. If it does not, but your fuel pump works when hooked directly to +12V, then you have a problem in the wiring between the fuel pump relay and the fuel pump.
My pump does NOT start pumping, is this related to my earlier question regarding pin 85 of the MAIN relay?
If that works, but it doesn't when the relay is in, you may have a bad relay. You can test the relay by applying +12V to tab 86 and grounding tab 85. Now check continuity between tabs 30 and 87 - there should be virtually no resistance. If there is a lot of resistance, or there is no continuity, replace the relay.
If the relay works, it may very well be the crank position sensor. Get out your multimeter and check the hole where tab 86 of the fuel pump relay goes. With the key on, there should be +12V there. If there is, then I would strongly suspect the crank position sensor.
If there isn't, you'll have to do the same tests on the main relay.
Looking forward to any help I can get, I have been working on this for 4 days now without reaching a meaningful conclusion. Nearly forgot to mention, there is a part in the engine compartment that is buzzing whenever the key is turned ON, I believe this is the ICV and that buzzing is what I want??
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Forgot to mention in my previous post that the fuel pump did work when I removed it from the car and applied 12V to it.
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Bringing this thread back up. :D
Disclosure: I have a little experience wrenching on E36s and E46s, but in no way consider myself a "mechanic." Bear with me.
I recently took possession of a 1991 318i. According to the previous owner, the car "suddenly died" and has not been able to restart since. He originally thought it was the timing belt, but discovered that nothing was wrong with it. He put the car back together, and decided he did not want to work on it. And now it's mine.
I've been reading the various forums regarding no start issues, and have discovered this is THE thread for this topic.
I've only had the car a few days and have not had much time to work on it.
1) Checked for spark on #1 coil (but did not check the other 3, should I?) There is spark.
2) I took the cover off of the fuel pump and can hear it working when I crank the car.
3) I am unable to smell gas from the exhaust.
4) Battery is fully charged.
My next diagnostics tests will be the CPS and CMP. I used my 5mm allen wrench to pop out the CMP today and discovered it to be coated in oil. Is that normal? Also does testing it require that pull it out, or should I leave it bolted in? Where should I make contact with the sensor to test it?
- If the fuel pump is functioning, but I do not smell gas from the exhaust, could it still be a fuel issue? A clogged fuel filter, perhaps?
- My friend suggested I drip some gasoline into the spark plug holes to see if it will turn over. Is he insane?
- The spark plug wires are in the order of 4-3-2-1 (4 starting at the windshield). I've read it might be 1-3-4-2, but the wires are not long enough to reach. What is the correct order?
Again, I'm sure these are really dumb questions, but any help will be greatly appreciated.
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Wire order is 4-3-2-1 (firewall to radiator). If the wire order is correct, the car knows how to do the firing order (1-3-4-2).
Once you get past the visual inspection for broken or badly frayed crank/cam sensor wires, the testing is done at the electrical connector end with the resistance settings of a multimeter. For your own sanity, mark which one is which. If the crank sensor is defective, your car won't start.
I've changed relays and a fuel pump to cure no-start issues, with the relays being the easier and far cheaper part to try replacing first:
http://www.m42club.com/forums/showthread.php?t=9396&p=77151
Unlike our M20 brethren, the M42 relays in the picture are on the firewall under a long black plastic cover. The M20s are under a short black cover just forward of the left front strut tower.
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Thanks for responding Mike.
I removed the Camshaft Position Sensor and tested it. 600Ohms.
I hope this is the problem. It should be 1250, correct?
Now to find a good one to borrow and test . . .
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You correctly found the fuel pump and the relays. In your photos of the sensor, its wiring, and your measurements, you have to do it at the black plastic end with the ignition off (just saw your last post -- looks like you figured that out).
If you're curious that your multimeter is working properly, ensure you have a fresh battery and your leads are seated properly. You can buy some resistors at Radio Shack and see how close your reading is to what's printed on the resistor package.
When you undo the black plastic connector, you'll see three terminals on its back side. Set your meter to resistance mode (2000 ohm scale) and put them across 1 and 2. For the "cam" sensor, a valid reading is between 1150 and 1410 ohms. For the "crank" sensor, a valid reading is between 490 and 590 ohms. Terminals 1 and 2 are the only ones that will give a valid reading. 1 and 3 or 2 and 3 will yield a 1 or OL (as in out of limits -- infinite resistance).
For what it's worth, the cam sensor goes on the upper connector, and the crank sensor on the lower. In other threads, crossing those two up leads to a no-start condition.
Adios for now,
RM
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Thanks again Mike.
It turns out the sensors were fine. I was using a very very old multimeter and I forgot to calibrate it.
Back to the drawing board. Bummer. . . .
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is the underside PCB of the fusebox cracked, etc?
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Any one have a CPS I could borrow (or buy)?...NEVERMIND....Got one coming from Zygmunt...
Thanks,
Dan
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Resurrecting the best diagnosis thread out there. . .
Here's my story. I bought a '91 318iS with 114k miles about 3 weeks ago. It had run flawlessly. (The only exception is when starting cold, it would stumble once or twice before settling in to a nice smooth idle.)
Earlier this week, I was driving home when the car hit a decent-sized bump, and the engine stopped dead. After coasting into a parking lot, the car would crank, but not fire. After getting towed home, I found this thread and started running through some of the diagnostics. Here's what I've checked so far:
1. After removing the rear seat and the fuel pump access cover, there's no sound coming from the fuel pump with the key on.
2. Stomp test gives me the 1444
3. Crank position sensor reads 550 ohms
4. Cam position sensor reads 1150 ohms
5. Fuse 11 is fine
6. I get no voltage at the fuel pump harness connector with the fuel pump relay installed and key on
7. I do get proper voltage at the harness connector with tabs 87 and 30 jumpered and key on, but the fuel pump still makes no noise when the wires are reconnected. Still no noise when jiggling the wires.
8. Fusible link doesn't show any obvious signs of having burned up
9. Check engine light does come on with the key in the on position
10. I haven't removed the fuel pump to test it externally because the gas tank is all the way full. As soon as I loosen the nuts holding it in place, gas starts leaking very quickly.
Putting all of this together, I'm led to believe that I have a bad fuel pump relay (6 & 7 above), and that I have a bad fuel pump (7). Is my logic sound enough to warrant ordering up a new fuel pump and relay, or should I perform more tests first?
Thanks in advance!
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If you have 12 volts at the connector and the pump is not humming or making some kind of noise then it's probably done for. You could hook 12 directly to the pump to see if it will start but it doesn't sound hopeful. Time for a new pump and at least you can rest easy that it will be good for another 150,000 miles.
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Mine did exactly the same thing a year ago. Hit a bump, actually, more like an expansion joint. I wouldn't have even noticed it except as you say, the engine died immediately. It was indeed a dead fuel pump. If your tank is too full, try jacking the passenger side of the car to raise the pump side enough to get the pump out without making a mess. If that doesn't work, try siphonng the gas out through the fuel pump exit. Also, find a DIY thread on removing the pump as it is tricky and involves some odd twists and contortions of the pump as it also holds the float (I think), or is quite near it.
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Mine did exactly the same thing a year ago. Hit a bump, actually, more like an expansion joint. I wouldn't have even noticed it except as you say, the engine died immediately. It was indeed a dead fuel pump. If your tank is too full, try jacking the passenger side of the car to raise the pump side enough to get the pump out without making a mess. If that doesn't work, try siphonng the gas out through the fuel pump exit. Also, find a DIY thread on removing the pump as it is tricky and involves some odd twists and contortions of the pump as it also holds the float (I think), or is quite near it.
Replacing the pump with a good used pump worked for me, but now I'm throwing a CEL at idle. Prior to the fuel pump failure, the car would stumble a few times on a cold start before settling in to a nice smooth ~750rpm idle. There were no CEL issues and no stomp test codes even with the dead fuel pump.
Now the engine stumbles harder and longer after a cold start. Even after it's warmed up, the check engine light comes on when idling for about a minute. Tapping the accelerator makes the CEL temporarily go away until the next time it sits at idle for about a minute. Stomp test gives me the ever-popular 1222 lambda code. Aside from the CEL, the engine runs smoothly and accelerates fine.
I found some split hoses under the intake, and patched them up with duct tape, with no effect on the cold start or the CEL. Adjusting the throttle to give a higher (1000rpm) idle had no effect on the CEL. Even at the higher-rpm idle, the CEL will still come on, while a quick stab of the throttle clears the light.
Any ideas on what might be the most likely culprit for the 1222 code before I start running through the whole list?
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Have you cleaned the ICV (idle control valve)?
When was the last time the O2 sensor was replaced ?
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Have you cleaned the ICV (idle control valve)?
When was the last time the O2 sensor was replaced ?
Cleaning the ICV stopped the cold-start stumble, and I haven't seen a CEL since cleaning it. I had to give it a thorough soaking with carb cleaner, and essentially "jump-start" it by apply 12v directly. After a couple of rounds of that, it finally started to hum again when reconnected in the engine bay. The bad news is that it only gave me a reading of 8 ohms, so I will need to replace it. But at least now I can keep driving it while I assemble the "mess under the intake" materials.
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My M42 Powered E30 recently died in similar fashion.
After reading this thread, I went out and checked the resistance of the Crank Position Sensor, and it read high. I traced the wire from the plug (under intake manifold) down to the sensor head and found that the wire was rubbing on a pulley and wore through...
Now, can anyone point me to a reputable online vendor that sells the Crank Position Sensor for a reasonable price? (The Cam sensor is easy to find, but Crank Sensor seems elusive). It's part number 12-14-1-721-968
Someone linked BAVauto which has it listed for $155. Is there any place that has it for less?
Pelican Parts lists it as a special order part, at dealer pricing of $177
On a similar note: Here is the Real OEM diagram that has the part number for the Crank Postion Sensor
(Item#11 "Pulse Generator")
http://www.realoem.com/bmw/showparts.do?model=AF93&mospid=47305&btnr=11_0156&hg=11&fg=10 (http://www.realoem.com/bmw/showparts.do?model=AF93&mospid=47305&btnr=11_0156&hg=11&fg=10)
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I don't recommend using cheap parts but here ya go............
http://www.partsgeek.com/catalog/1991/bmw/318is/engine_mechanical/crank_position_sensor.html
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When my CPS went south, the best price I found was through http://www.bimmerparts.com. The part is NOT listed on their site (at least not at the time when I was looking), however, I just emailed them and gave them the CPS part number and also stated I needed the Crank Positioning Sensor NOT the Cam Sensor. IIRC, I think I had paid $160 which included shipping costs to NJ. I ordered from bimmerparts only because I have ordered many BMW parts from him in the past, never had an issue, parts are genuine, shipping is quick and customer service is excellent.
FYI - http://www.realoem.com shows the genuine BMW Crank Positioning Sensor as the "Pulse Generator", so if your BMW Dealer cannot locate the part as a "CPS" or "Crank Positioning Sensor", tell them to look up "Pulse Generator". It is BMW part # 12141721968.
It is part # 11 in this schematic diagram on realoem:
(http://www.realoem.com/bmw/diagrams/b/l/52.png)
That CPS is NOT cheap. If you have a BMW CCA Member #, you can get a discount on the part at your local BMW Dealer - but then again, every BMW Dealer can charge their own price for the part, since they are independent Dealers and don't follow a standard price structure.
This thread has a TON of excellent tech for the non-start issue - if you have completed all of the process of eliminations of the other parts for a non-start issue and the car still will not start, 98% of the time, it's going to be a dead CPS... and for whatever reasons unbeknownst to all of us, that M42 DME will NEVER spit out a failure code for a failed CPS, even though an actual code exists... I guess the BMW programmers forgot to hardcode that one into the M42 DME's... LMAO...
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I don't recommend using cheap parts but here ya go............
http://www.partsgeek.com/catalog/1991/bmw/318is/engine_mechanical/crank_position_sensor.html
JUST AN FYI!!!
That pic or part in that above link is totally incorrect for the M42 E30 Crank Positioning Sensor! BE AWARE of what you're buying, because some of these BMW aftermarket vendors are showing totally incorrect parts for the E30 M42 engine... The correct sensor should have a very long black wire attached to it (about 3ft+), with a male connector end which gets connected to the black electrical distribution box located under the intake, on the driver's side of the engine...
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JUST AN FYI!!!
That pic or part in that above link is totally incorrect for the M42 E30 Crank Positioning Sensor! BE AWARE of what you're buying, because some of these BMW aftermarket vendors are showing totally incorrect parts for the E30 M42 engine... The correct sensor should have a very long black wire attached to it (about 3ft+), with a male connector end which gets connected to the black electrical distribution box located under the intake, on the driver's side of the engine...
If you read under the image at that link it states "Image is not vehicle specific" which means it is not the part you'll recieve. I suggest if you have any questions for them to call them with the part number and describe the part.
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If you read under the image at that link it states "Image is not vehicle specific" which means it is not the part you'll recieve. I suggest if you have any questions for them to call them with the part number and describe the part.
D'OH! I did not see the "fine print".... but anyhow, as you also said too - for those seeking to buy that part (which is awful cheap), definitely make sure it's the correct CPS (for an E30 M42) and not for an E36 M44...
:)
take care!