M42club.com - Home of the BMW E30/E36 318i/iS
DISCUSSION => Engine management => Topic started by: sfinsf on February 27, 2012, 08:18:23 PM
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during some spirited driving on a twisty mountain road, my little german decided to hesitate under heavy acceleration and then completely give up and stall after reaching the summit within about a 1/4 mile after the hiccup. It would start after cranking and lots of pumping of the accelerator, but then stall within 30 seconds. It did this three times and finally, after no signs of coming back to life, I decided to neutral coast down to a resting spot. That's fun w/o the power assist brakes!
stomp revealed 1244
Had it towed home :(
after much reading....
FP relay making activating sound, Fuel Pump sadly quiet
pulled fuel pump, tested, in working order, leads me to Crank PS, no continuity, so I check Cam PS just to see that I'm doing it right... nothing.
Is it likely that they retired together as a team? Does this indicate or imply a larger ill? Am I a retard noob and failing a simple continuity test? :confused:
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You're not failing the continuity test at all. You'll get better results with ohms.
:D
680 or so on the crank pins 1 & 2...and 1240 or so on the cam pins 1 & 2. Pins 1-3 and 2-3 should be very high, min 300k ohms IIRC.
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also, these fuel pumps can die in situ, or appear to, then come to life when removed, or even tapped hard with a wrench..sometimes it is flakey connections on the pump, and sometimes the pump is going bad, but will work after being moved or tapped on. if this is the case they may do this a few times before they die for good.
Geoff
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dave, not sure I'm following you. thought I was testing for ohms/resistance by doing the following
This is from my meter manual:
7. Resistance/Continuity Measurement For resistance and continuity testing POWER MUST BE OFF:
1) Fully seat the test leads in the input jacks.
2) Set the function/range switch to the Rx1K position (resistance indicated multiplied by 1000) and short the test leads together. Using the zero ohms adjustment dial, slowly turn the dial until the needle indicator reads -0- ohms at the right end of the ohms scale. If the needle will not zero, replace the internal battery with a new 1.5 volt AA size battery (see Battery Replacement).
3) Touch the test leads to the resistance or non-energized circuit to be measured. Measure the value of the reading on the green ohms scale and multiply the reading by 1000. If you’re making basic continuity tests, the needle indicator should move all the way to the right side of the ohms scale if continuity exists.
After performing this test with both of the sensors pulled out, no matter what lead I touch to there is no response on the needle (its an analog meter)
wrong setting? wrong test?
Geoff, not getting 12 volts at pump when turning over engine, makes me think that the relay is not getting its signal to close and power the pump. I focused on solid connections while I had it out.
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not sure what happened to my other post, still unclear what I did wrong to test the cps, but went at this issue again with the DIY no start from an old post and bavauto
http://www.bavauto.com/newsletter/2007_n407_newsletter.pdf
after some time with my multi tester discovered that my fuel pump relay is dead, ordered a new one, waiting to see what happens next.
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Sorry - missed your earlier post. It was moderated, I approved it for you. I didn't know you were using an analog meter.
Did you jump the fuel relay socket to test the pump? IIRC it's pins 30 & 87 with a short bit of wire. I have one with male spades in the car just for such testing.
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I did fuel relay jump and it proved that the pump is happy and the relay is not. Hoping that the relay is the only thing that is dead this time around. Learn something new every week with this sweet little car. Thanks!
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If it's not the relay it's likely the CPS. Without the crank sensor signal the computer won't turn on the relay, so no fuel pump.
On the crank sensor wire, pins 1 & 2 need to be about 640 ohms, pins 2 & 3 and 1 & 3 should be very high, like 300K ohms or so. I looked at your earlier post...you did test the sensor, right? Not the harness heading back to the computer, right? If so, don't do that. Doing a resistance or continuity test on the harness can damage the computer.
I'd advise getting a cheap multimeter at Radio Shack, Sears or Harbor Freight. They're self-calibrating, do many tests, and are very reasonable. I bought a few of the $4.99 HF units (along with some of those cheap LED flashlights) just to have in the cars. You never know when you'll need one!
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some progress made, still no start.
- bought digital meter
- Cam PS tested - 1240 ohms between pins
- tested for voltage on each of the four connections on the coil block
- new Fuel Pump and Main Relay
- retested fuel pump with jumper wire, it hums away and plays nice
- started pulling out hair so I pulled fuel line just before fuel filter under car, no pressure, no fuel squirts out when I perform jumper at relay
- pulled pump out of tank, it makes noise, but doesnt pump any fuel.
now this sounds dumb, but does the pump run and not pump if there are issues elsewhere, or is this pump ready for the ball peen hammer burial process?
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Am I being punished? Two posts now and nothing is showing up?
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wanted to let you all know the latest on this issue.
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I don't know, but I was on the forum several times between yesterday afternoon and this morning and there was nothing showing when I hit new posts. An hour later I refreshed the page and had half a dozen new posts from the preceding 12 hour period.
Cyber-space lag?
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It's more of a Dave-lag...I missed that post. The "new posts" link doesn't seem to work as I'm assuming it does. Not sure why, but it misses updated posts all the time for me. Combined with the uptight spam filter, it makes moderating a bit of a chore.
Anyhow, what's the results of the crank position sensor resistance test? The cam sensor looks good. That crank sensor is a very common no-start problem. If there's zero resistance on pins 1 & 2 of the CPS, it's dead (internal short) and the DME won't receive a signal. Then the DME refuses to signal the fuel pump relay...and you get no fuel pump power at all.
Jump the fuel pump relay socket pins 30 & 87. The pump should power up when you turn the key. You should hear the pump...and likely the sound of fuel flowing through the rail & FPR. The car might even be able to start...I ran my car that way when I bought it for a little while, just pulled the jumper wire out after diagnosing so I didn't kill the battery.
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the fuel pump runs, but does not pump fuel. disconnected just before the filter, same thing. disconnected at the connection under rear seat, still no fuel but it engages electrically. Now I'm not super bright, but I'm gonna say my fuel pump is dead.
But just to make sure, has anyone ever run into this before? Is there a sensor that would tell the pump to run, but not move any fuel thru it? That seems a bit over the top, but we are talking about german engineering here!
I really dont want to drop coin for a new FP at over $250 bucks
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Might be that the pickup screen is plugged. You can fit a generic fuel pump if its bad. You can verify it if you borrow a fuel pressure gauge...usually an Advance or Pep Boys will loan them if you leave a deposit.
The gauge should see about 43psi running off a tee, or up to 80psi if you dead-head it with the gauge.
Worst case scenario, just buy the pump, not the whole OEM assembly. Walbro makes one and some members have reported success with cheaper TRE pumps. Here's a thread about the TRE 340 fuel pump (http://m42club.com/forums/showthread.php?t=9856). That lists for only $70 here, (http://trefuelpumps.com/i-89173-ford-mustang-4-6-gt-1996-1997-255-lph-fuel-pump.html) you just need to be a bit handy to install it.
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I've seen the short rubber coupling hose fail on some pumps. It has a sort of dampener assembly but it could be leaking or it's been replaced by a poorly fit hose. It's worth pulling it out and having a look. Fairly easy procedure.
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to answer your question, I have seen fuel pumps go bad where they would "make a noise" but not pump fuel. if the fuel supply to the pump is unrestricted, then the pump must be bad.
Geoff
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Thanks guys, ordered the TRE pump today.
Dave, thanks for the link. The best part was that I discovered in the process of reading the entire thread, "Zen and the Art of e30 Maintenance".... Holy Crap, if you havent seen his build, it's a must read. Serious M42 porn!
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Alright guys, could use some more input/help. Still battling this no-start. The list is long now...
- new fuel pump TRE 340, it's getting 12v and is pumping fuel to rail
- bought stethoscope, confirmed injectors are working, no way to know for sure if they are providing proper spray
- have spark, checked all wires and plugs
- checked all vacuum hoses
- both cps test at appropriate ohm readings
- new battery
- new main and FP relays
- new plugs
what is next?
It cranks solidly, makes little back fire sound in intake/airbox, plugs are wet after cranking it over a bunch
I'm thinking at this point that it could either be,
- not enough fuel pressure?
- bad injector? Would that result in a no-start?
Please chime in....:confused:
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Weird. It sounds like the fuel system has been properly covered.
Here's a long shot, but it happened to me once. The EPROM in the ECU was loose in its little socket. It took forever to think to look in there, but I eventually did & it wasn't seated. Did you ever install a performance chip or anything?
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no, I havent messed with ECU at all, I will look at it today. Any way I could pay you for some onsite diagnostics, I'd rather give you money for your new motor than give it to a random machanic.
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Where are you located? I usually take FOOD as payment for work for fellow enthusiasts!
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I'm in Moraga, food, beer, cash, whatever you need the most! Tried a bump start today, no luck.
Inspected ECU with my limited experience and all seems well and connected solidly.
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As far as helping out...I am out of commission for a little while. My M42 had a timing chain oops, and I am having a custom motor built to replace it, so I don't have a car at the moment. I also fly to Seattle for work every Sunday-Monday, so that doesn't help anything! I bet I can work out a Saturday to check it out though.
At this point, it sounds like the issue is just going to end up being ONE stupid thing. If it is getting fuel and spark, and the crank sensor is working, it should run. If the fuel or spark was malfunctioning, it should at least run POORLY. The total lack of running indicates that something critical in the control system is pooped out or disconnected. Have you cleaned the idle control valve? Does opening the throttle when trying to start it help at all?
The motor should at least run (badly) if the throttle sensor or air meter were busted. The same goes for the ignition coils...all 4 would have to be totally dead to prevent it from running at all. I think that something in the controls is pooped out so that the ECU is not firing the ignition coils, because if you have fuel, some ignition activity would lead to some sort of operation.
Did you remove the ECU entirely? Did you shake it to see if anything was rattling around inside? I would assume that a loose EPROM would mean that you got NO fuel injection at all, so it seems unlikely that this is the culprit. Since the car died while driving, it obviously isn't like you unplugged or switched something.
The one other thing I can think of is that the ignition coil driver IC crapped out. It has happened. The coils get constant 12V, and the ground gets switched through the ECU, so getting 12V at the coils isn't indicative of anything other than that the main relay is working. Is there anyone local to you with a spare ECU, or just the one out of their M42 that you can plug in to see if that helps? At this point, a dead ignition driver IC seems like the most likely culprit. Sorry I didn't think of that sooner.
I'd lend mine to you, but the car is 20 miles away and not running lol. There are other Bay Area guys on here...surely someone can lend a hand and ECU!
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sounds like a mighty busy schedule!
gave the ICV a little clean and inspect when I removed the mess under the intake, but what is best, complete method?
when you say "open the throttle" are you referring to removal of the boot? or manually or what?
did not pull ECU, i will try that next. Is the Ignition Driver IC an electronic component on the board of the ECU that can be replaced?
Appreciate the input!
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Sorry, when I say "open the throttle" I mean to push the gas pedal a little. If the ICV is stuck shut, opening the throttle a little like that would let in some air.
If the coil driver is dead, you COULD solder in a replacement, but I don't think that that IC is commercially available. You would have to pull one from a known-good ECU...and at that point, you might as well just swap the ECU. They are really cheap on the forums. It would be fun to find some sort of modern driver IC with the same pinouts & develop a database of new-replacement parts for our aging ECUs though! I think it's called Megasquirt........
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so I finally gave in and took my 318is into a shop to see if they could get it to start. After 4 days of testing and diagnosing, they called to say they had given up. I purchased a used DME at one point and that seemed to make things worse. So far all sensors test out good and everything seems to operate on it's own, it's when all are together that some part of the system doesn't function as it should. I'm still in a no start situation and sadly have to tow my girl home and start replacing parts.
If anyone is following this thread, here is where I am going next.
- purchased OEM fuel pump, to replace TRW that I just recently installed
- purchased new Cam sensor
right now the fuel pump is producing correct pressure, the issue is that the DME is not firing the injectors (or so it seems), when bench tested they all work as they should
fuel pump fuse blows according to tech, so I am hoping that the OEM model will eliminate this issue. :mad
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I'm about ready to give up and sell my 318is. No one can seem to bring this engine back to life. Anybody have any new ideas on what to check/look for? We have replaced and tested so much stuff I'm beginning to lose it. This damn M42 has all it needs to start but just wont come back to life.
Please help!!
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I'm about ready to give up and sell my 318is. No one can seem to bring this engine back to life. Anybody have any new ideas on what to check/look for? We have replaced and tested so much stuff I'm beginning to lose it. This damn M42 has all it needs to start but just wont come back to life. Please help!!
It appears you have spark, air and fuel, but do you have compression?
Looking through your thread http://m42club.com/forums/showthread.php?t=14555 regarding the timing chain makes me wonder if the timing sprocket on the crank was also changed and if not, is it worn enough for the chain to have skipped a tooth?
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It appears you have spark, air and fuel, but do you have compression?
Looking through your thread http://m42club.com/forums/showthread.php?t=14555 regarding the timing chain makes me wonder if the timing sprocket on the crank was also changed and if not, is it worn enough for the chain to have skipped a tooth?
when it was at the shop, the mechanic tested compression and confirmed that it was very good. He also confirmed that the timing was correct based on a visual crank check
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Time for another DME? You said the car seemed to run worse when you swapped a replacement in; did you happen to swap the original back in to see if it ran better? Maybe try a DME from a running car? I believe I have one that I could send your way.
If everything seems to be working correctly during bench tests, but not when installed together on the car that would seem to indicate wiring problems. Check for chaffing on the wiring bundle going to the DME?
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Time for another DME? You said the car seemed to run worse when you swapped a replacement in; did you happen to swap the original back in to see if it ran better? Maybe try a DME from a running car? I believe I have one that I could send your way.
If everything seems to be working correctly during bench tests, but not when installed together on the car that would seem to indicate wiring problems. Check for chaffing on the wiring bundle going to the DME?
I have another members DME on the way, but Thanks though!
So with the original DME, it just cranks away and doesnt really seem to be catching or doing anything. The replacement DME is much different, engine gets really close to starting but never makes it all the way, we shall see what the next DME does, should be here in a day or two.
My mechanic was completely baffled by the fact that all the individual components, sensors and elements tested good and worked independently but when they all try to come together, something is missing or not occurring.
I am reluctant to do anything significant with the harness because I'm afraid I will be adding one more thing to check.... do you have some specific things/places to check that have proven successful for you?
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third DME arrived today and made no difference in the no-start condition.
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I tried to check the previous posts, but couldn't see if you mentioned this...
When you crank away, do you smell raw gas at the tail pipe, or see wet spark plugs or anything? If you have a working fuel pump in there and get the proper fuel pressure, but there is no sign of fuel getting to the cylinders, then at least that narrows it to the injection system. That could be due to a broken wire in the injector harness. It isn't too hard to check.
With the key removed form the ignition, unplug the injector harness from the black wiring box and test the resistance between pins 1-2 and 1-3. In both cases you should see something like 6-9 Ohms. If you see 14-16 Ohms, a really high value or near-zero then there is a broken wire or short in the injector harness. Also check for 14-16 Ohms between pins 2-3. If that checks out, then put the key in accessory position (the second click where the gauge cluster lights up) and look for 12V on pin 1 on the main black box.
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I tried to check the previous posts, but couldn't see if you mentioned this...
When you crank away, do you smell raw gas at the tail pipe, or see wet spark plugs or anything? If you have a working fuel pump in there and get the proper fuel pressure, but there is no sign of fuel getting to the cylinders, then at least that narrows it to the injection system. That could be due to a broken wire in the injector harness. It isn't too hard to check.
raw gas and damp plugs with black soot after much cranking. replaced fuel rail, FPR, injectors and elec bar just yesterday with no change in status.
With the key removed form the ignition, unplug the injector harness from the black wiring box and test the resistance between pins 1-2 and 1-3. In both cases you should see something like 6-9 Ohms. If you see 14-16 Ohms, a really high value or near-zero then there is a broken wire or short in the injector harness. Also check for 14-16 Ohms between pins 2-3. If that checks out, then put the key in accessory position (the second click where the gauge cluster lights up) and look for 12V on pin 1 on the main black box.
pin test revealed 10 ohms at 1-2 and 1-3
18 between 2-3
12+ volts in pin 1 male at main box
oh how I wish that would have been it.... anything else?
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Those values sound just fine. Bummer.
1) You said you measured fuel pressure and got acceptable readings. Where and HOW did you measure this? It sounds like you popped the input hose to the fuel filter and measured on that, with it disconnected from the rest of the system?
2) You said that you see no signs of fuel being injected into the motor (no gas smell at the tailpipe)?
If 1 & 2 are true, it is possible that you have a completely dead fuel pressure regulator. I would assume that it is designed to fail open to prevent the system from blowing up. It is exceedingly rare that they fail, but that may be why nobody could diagnose it since that is probably the last thing they would check.
The other thing coming to mind right now, and this is a really really long shot, is that the CPS wires are damaged somewhere between the wiring box & ECU. You could try checking continuity between the receptacle terminals on the wiring box and the main ECU plug. The pins numbers are all listed in the scans I posted here:
http://m42club.com/forums/showthread.php?t=5098
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Nothing constructive to say; just....I think the FPR is the only piece he hasn't replace in the fuel loop... but I'm betting it's an electrical gremlin(rubbed wire behind the dash)
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Nothing constructive to say; just....I think the FPR is the only piece he hasn't replace in the fuel loop... but I'm betting it's an electrical gremlin(rubbed wire behind the dash)
the FPR has been swapped out with a salvage bought one along with fuel rail and elec bar and injectors
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Those values sound just fine. Bummer.
1) You said you measured fuel pressure and got acceptable readings. Where and HOW did you measure this? It sounds like you popped the input hose to the fuel filter and measured on that, with it disconnected from the rest of the system?
2) You said that you see no signs of fuel being injected into the motor (no gas smell at the tailpipe)?
If 1 & 2 are true, it is possible that you have a completely dead fuel pressure regulator. I would assume that it is designed to fail open to prevent the system from blowing up. It is exceedingly rare that they fail, but that may be why nobody could diagnose it since that is probably the last thing they would check.
The other thing coming to mind right now, and this is a really really long shot, is that the CPS wires are damaged somewhere between the wiring box & ECU. You could try checking continuity between the receptacle terminals on the wiring box and the main ECU plug. The pins numbers are all listed in the scans I posted here:
http://m42club.com/forums/showthread.php?t=5098
1) I actually have not measured the fuel pressure, the BMW tech said that he found acceptable pressure. I have not been able to find one easily that will measure in line.
2) There are signs of fuel. Pulled line going into fuel rail and cranked engine to confirm fuel was getting to the rail. pulled each plug after cranking and plugs were wet. smell of fuel at tailpipe which smells like gas thru CC not fresh 91 octane
3) FPR on second rail that I tried from Dbl 02 salvage. Can't imagine that both are dead but it is possible.
I will check your long shot cuz it's all I got. only I'm not sure of what I'm testing, diagram only lists speed sensor, is that the crank or cam? either way, it's pin 74, correct?
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Pins 67 & 68 are the ones connected to the CPS, in the last diagram in the post.
If you swapped fuel rails and have fuel in the cylinders, then it isn't that.
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Pins 67 & 68 are the ones connected to the CPS, in the last diagram in the post.
If you swapped fuel rails and have fuel in the cylinders, then it isn't that.
damn, well thanks anyway, if you think of anything else let me know.
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It's no consolation, but I think that you get the award for the most mysterious no-start problem. Is there nay way that you mixed up the ignition coils / wires & the wrong ones are firing? Check to make sure that you have a good connection between the wiring box and pins 67 & 68 at the ECU too.
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Like I mentioned in PM, have you grounded the plugs to the valve cover while cranking to make sure they are sparking?
Also on mine when I had similar issues on engine reinstall I had to trace the ECU pin for each coil to the coil itself to veryify which was which. You can also do this by applying a voltage to the ECU connector pin and measuring which one has the juice on the other side to identify without ripping into the harness.
If any of the cylinders are swapped the car will not run. The ignition is sequential, not wasted spark.
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Like I mentioned in PM, have you grounded the plugs to the valve cover while cranking to make sure they are sparking?
Also on mine when I had similar issues on engine reinstall I had to trace the ECU pin for each coil to the coil itself to veryify which was which. You can also do this by applying a voltage to the ECU connector pin and measuring which one has the juice on the other side to identify without ripping into the harness.
If any of the cylinders are swapped the car will not run. The ignition is sequential, not wasted spark.
Yup, grounded plugs to chassis, confirmed spark to each plug from each wire
will test out the individual wires, really no reason why they would have been swapped, again this is not an engine swap issue, no one has moved any significant wiring since is was running perfectly, but I will still check it to cross it off the ever growing list
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so I traced and confirmed the wiring and sequence involved with the step by step start up procedure as outlined in the thread. http://m42club.com/forums/showpost.php?p=47710&postcount=4
all was good
then tested my fuel pressure, pretty much confirmed that my mechanical fuel delivery system has no faults that I can find. The only aspect that could be at fault is the actual firing of the injectors, which essentially is electrical
got another afm from another member installed, no change in no-start
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Totally out there with this one...
Could the crank have broken up front so that the timing assembly is not being driven? If the Woodruff key goes, that could happen. Run the starter and have someone look in the oil filler hole to see if the chain is being driven. You could try with the valve cover off but that would make a big mess.
Since the timing was checked and was good, this is probably totally unlikely. It sounds more and more like some sort of ignition gremlin.
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Totally out there with this one...
Could the crank have broken up front so that the timing assembly is not being driven? If the Woodruff key goes, that could happen. Run the starter and have someone look in the oil filler hole to see if the chain is being driven. You could try with the valve cover off but that would make a big mess.
Since the timing was checked and was good, this is probably totally unlikely. It sounds more and more like some sort of ignition gremlin.
seems unlikely that a mechanical is causing this, however it did fail under acceleration. But every test on the system has been positive...
I agree that the electrical system has some sort of an issue. Everything mechanical is testing out.
Any suggestions on finding the gremlin?
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just sharing my experience. a few years ago, I had a similar problem. I tried troubleshooting it for a weekend, but I didn't have time to finish. took it to a shop, and it even confuzzled him. he did eventually find out the problem. it was the main crank pully. if you look at it, the rubber vibration dampener is what holds the timing marks for the hall effect pickup for firing the injectors and iginition. the rubber had seperated and the "timing disc" had slipped, resulting in timing being completely off.
I'd go and see if the "timing disc" can be moved by hand, or if there is any play what-so-ever. also, he had to replace the sensor, as he said the disc breaking free smashed into the sensor. he even showed me the old pully. it was completely separated from the main pully. it blew me away. I just couldn't figure out how BMW engineers thought it would be a good idea. I was pissed and happy at the same time. I had my BMW back, but I was completely pissed off that BMW engineers could do something so stupid.
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If it's not the relay it's likely the CPS. Without the crank sensor signal the computer won't turn on the relay, so no fuel pump.
On the crank sensor wire, pins 1 & 2 need to be about 640 ohms, pins 2 & 3 and 1 & 3 should be very high, like 300K ohms or so. I looked at your earlier post...you did test the sensor, right? Not the harness heading back to the computer, right? If so, don't do that. Doing a resistance or continuity test on the harness can damage the computer.
I'd advise getting a cheap multimeter at Radio Shack, Sears or Harbor Freight. They're self-calibrating, do many tests, and are very reasonable. I bought a few of the $4.99 HF units (along with some of those cheap LED flashlights (http://www.robustbuy.com/led-lighting-gadgets-led-flashlights-c-505_1027_730.html)) just to have in the cars. You never know when you'll need one!
Yes that would help in many cases. There is not harness is going to head on you computer for sure..