Author Topic: fuel pump/non-start issues - been doing lots of research, still NEED HELP... please >  (Read 44116 times)

Cobra Jet

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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...
« Last Edit: April 22, 2008, 07:53:49 AM by Cobra Jet »
- Phil
1994 Cobra coupe #0013
2011 Genesis Coupe
2011 Tucson GLS

Scany

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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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Cobra Jet

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Quote from: Scany;47695
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?
- Phil
1994 Cobra coupe #0013
2011 Genesis Coupe
2011 Tucson GLS

ak96ss

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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.



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.



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.



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.



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.



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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John in MD
uh, it's a '91 318is, like everyone else...

RED IS 91

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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 .
« Last Edit: May 29, 2010, 06:01:12 PM by RED IS 91 »
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Cobra Jet

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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)?
- Phil
1994 Cobra coupe #0013
2011 Genesis Coupe
2011 Tucson GLS

Cobra Jet

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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)...
- Phil
1994 Cobra coupe #0013
2011 Genesis Coupe
2011 Tucson GLS

Cobra Jet

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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!
« Last Edit: April 22, 2008, 09:55:27 AM by Cobra Jet »
- Phil
1994 Cobra coupe #0013
2011 Genesis Coupe
2011 Tucson GLS

PartsCar

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Cobra Jet

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Quote from: PartsCar;47720
try autohausaz.com

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..
- Phil
1994 Cobra coupe #0013
2011 Genesis Coupe
2011 Tucson GLS

ak96ss

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Quote from: Cobra Jet;47712
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!
« Last Edit: April 22, 2008, 11:23:54 AM by ak96ss »
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John in MD
uh, it's a '91 318is, like everyone else...

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Cobra Jet

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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...
- Phil
1994 Cobra coupe #0013
2011 Genesis Coupe
2011 Tucson GLS

RED IS 91

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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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ak96ss

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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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We're here to preserve democracy, not practice it.
[INDENT]- Captain Frank Ramsey, Crimson Tide[/INDENT]
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John in MD
uh, it's a '91 318is, like everyone else...