M42club.com - Home of the BMW E30/E36 318i/iS
DISCUSSION => Engine management => Topic started by: Broach318 on February 11, 2013, 03:07:32 PM
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FIXED!! SEE MY LAST POST FOR SOLUTION!
Hello everyone this is my first post to this site. I have searched everything I can and would really like some advice from people who know the M42 motor!
Here is the story I have a 91' 318is. We recently went through pulled the motor, tranny and replaced about everything. It ran amazing for about 8 months, fuel pump went out about 3 months ago I replaced it with OE pump along with filter. Car ran perfect now about a month ago, out of the blue it starts acting up. After the car is warm it will cut out RPMs around 4500 and seems to just run horrible just sputtering out sporadically like its just not getting fuel, which the fuel pump and filter are brand new. Also it starts fine when cold but after its warm and sits for a few minutes it takes about 10-15 turns before it starts, also started out of the blue at the same time as the other problem. Did the stomp test got the bad o2 sensor code 1221. So I got a new o2 sensor, same thing. So we got a new FPR, started it did and drove to get fuel 15 minutes away. It did the same thing. Got the gas and left and it ran perfect smooth pull up to 6300RPM all gears. The next day it does fine. The next day its back to running like crap again. I am absolutely baffled and frustrated to no end. If anyone could lead me in the right direction i would be greatly appreciated! Thanks so much advance guys!
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One my colleague had similar problem and after few months fight he found front pulley http://bmwfans.info/parts/catalog/E36/Coupe/Europe/318is-M42/browse/engine/belt_drive_vibration_damper-2/ part #1 which is with rubber damper and at certain revs it starting to vibrate and give faulty signal to the engine ECU. Hope it will help ;)
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I had a few ideas, nothing specific though.
Check to make sure the fuel supply and return lines aren't swapped at the intake manifold.
Check for vac line leaks.
Check coolant and air temp sensors. They should have very high resistance when cold (10K Ohms IIRC) and very low when hot (300ohms?).
Check fuel pump and main relays with a jumper to see if the problem goes away. Sometimes they age a bit and don't give 100%.
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Okay I will look into that, I was leaning towards the CPS ( cam position sensor)? what do you all think? Its just super weird, two days ago it runs 120% and the next day its running like crap. I just don't get cars sometimes :/
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You said that this only happens when it's running warm, right? In that case your DME might be stuck in the warmup loop & injecting way too much gas for a hot motor. So I'd suspect the closed-loop sensors like CLT, IAT, TPS and associated wiring.
Our cars are famous for intake manifold leaks too. The rat's nest of vac lines under the manifold is the usual culprit. Eliminating the TB preheater and associated Medusapalooza is a well-tested preventative.
I've also noted the occasional bad plug wire or coil. Typically that will only happen when they overheat. Troubleshooting the coils is a PITA, easiest to check the plugs for one that's different and then swap a known good coil pack and see if the problem persists.
The car will go back to open-loop at wide-open throttle...when the car is bogging, can you fix it by flooring it?
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Had similar symptoms with a Mercedes, was the mass air sensor being twitchy.
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@ Dave, Correct it only does this when it gets warm. No its like it is literally hitting a rev limiter at 3-4500 RPMs its sporadic which makes it very odd. Changed the spark plugs a few days ago and did nothing.. Mass air flow was sent to a guy to be rebuilt and we checked it and it is working fine. I will look into some of the vac leaks in and under the manifold. Thanks!
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An update today I drove it around trying to figure out the cause. At first it ran okay (car runs okay until it warms up to running temp and thats where it begins. The higher gear you are in the lower the RPM will cut out, 2nd is around 4 3rd is 3500 4th is about 25-2800 and 5th is anywhere from 1800-2300) so I did the stomp test. It throws a code only in 5th when its bogging out bad and its 1221 for the oxygen sensor, which is new. So I unplugged it and it ran perfect, very smooth pulls all the way to 6300 in all gears (1st,2nd,3rd) drove it for another 10 minutes or so cut it off let it sit for 10 minutes. Started it up ( still does not want to start like it should) and it drove perfect with the O2 sim still unplugged. I got to a stop sign plugged it back in, and it still drives good. Although not quit as good as unplugged, it still went to 6300. Just personally didnt feel as strong as when it was unplugged. I took some videos, I will post them when I figure out how to get them on here. Thanks a lot guys, all input is really appreciated.
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http://www.youtube.com/watch?v=AHrhHLXcP38
This video shows the bogging out. ^^
http://www.youtube.com/watch?v=ELrT2gGckgc
This video is after I unplugged the O2 sensor
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I posted two videos, its telling me a mod has to review it first... But anyways Ive been researching on this for hours now. And Ive found a few possible solutions. The spark plug wires, AFM, crank sensor. Other than that I really have no clue, as the fuel pump, filter, FPR are all new, and we just pulled the motor and fixed everything. ( 8 months ago). All of this happened overnight, ran great and that next day was 180* difference.
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You're making some progress! BTW - I approved your posts & deleted the duplicates. The site has a lot of trouble with spammers so the filters are pretty tight...sorry for the inconvenience.
Here's my thoughts...I suspect the O2 sensor is OK, but it's reading out-of-range...probably too rich.
Humor me & put a multimeter on that coolant temp sensor both when it's cold and when it's warmed up. Let me know how many ohms it's putting out. If the CLT is bad it'll tell the DME that the car isn't fully warming up, so the DME compensates with more fuel - running a pretty rich mixture especially at high RPMs. In that case you'll get a 1221 as the O2 reads really rich.
Alternatively, intake air leaks or even a bad ICV will cause O2 codes - the unmetered air leans out the fuel mix and you get a 1221. Plugged fuel injectors can do the same thing.
By any chance you haven't recently sealed the intake or exhaust with a silicone RTV, have you? Some of those silicone make-a-gasket sealers can damage O2 sensors.
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Yeah, its just getting frustrating. Okay well i checked the coolant sensor got 2.250 OHMS while car was cold, as it warmed up it slowly dropped, so thats good. Today I drove it trying to figure it out, and was worse even cold it would barley go over 1500 rpms and actually have zero spark. I could give it full throttle and would completley bog out. got the check engine light, stopped on the spot and did the stomp test and got the 1221. So I unplugged the O2 sensor and it ran better not perfect by any means but enough to get on the road and drive, like it runs good until you get to a certain rpm or load and it just like its getting the fuel cut to it.
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One my colleague had similar problem and after few months fight he found front pulley http://bmwfans.info/parts/catalog/E36/Coupe/Europe/318is-M42/browse/engine/belt_drive_vibration_damper-2/ part #1 which is with rubber damper and at certain revs it starting to vibrate and give faulty signal to the engine ECU. Hope it will help ;)
And here's another thread with "cuts out at XXXX RPM". Turned out to be the harmonic balancer just as romkasponksa suggests.
http://www.m42club.com/forums/showthread.php?t=14814
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@keflaman did your car have the same symptoms as what I am experiencing? Or what symptoms did you have exactly? Thanks!
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It wasn't my car, but I picked that thread specifically because it was one of the few that the OP actually posted the resolution. I dunno, maybe the rubber compound has more give when it's warm and it's throwing the timing off; when everything cools the rubber firms up and timing is correct.:confused:
Based on that theory, everything is copacetic and you're tootling down the highway. Meanwhile, the rubber in the harmonic balancer warms up by heat in the engine compartment and becomes more pliable. When you accelerate the crank speeds up, but drag induced by the AC compressor and alternator belts distorts the rubber and that throws the timing off and the DME retards or shuts down the engine.
The car is parked for some time, everything cools down and the car magically starts up again running fine and then...
Just some food for thought: What part of the country do you live in? Have you experienced any wild temperature swings? We've gone through a couple cold-hot-cold days with 30-40*F temperature variations.
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Well thats the odd thing, today it was doing it bad while it was cold. I feel like its something ignition related, like maybe spark plug wires, coils. Or even the cats are clogged causing it to throw the O2 sensor off and trigger the 1221 code ( bad o2).. I don't know its weird stuff. I live in SC and car stays in the garage.
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What does anyone think about the possibility of a clogged fuel filter? It was replaced in june, but it fits the discrition of a clogged filter. Long cranks 10-20 turns, horrible acceleration under load...
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Toss a gauge on it and see what your pressure looks like. Dead-heading a healthy fuel pump might get you 80psi...but if you tee the supply line you should see a bit more than 2bar - 40-ish psi at idle.
A clogged cat is unlikely. Our cars have them bolted on almost as an afterthought...downstream of the O2 sensor.
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Did you check the position sensors? Crank sensor should be about 640 ohms, cam sensor about 1200-ish.
Okay well i checked the coolant sensor got 2.250 OHMS while car was cold, as it warmed up it slowly dropped, so thats good.
Do you have the Bentley or BMW ETM? Here's a few quick tests:
Specs on the CTS - according to Bentley, you should see 5VDC between the brown/red wire and ground from the DME. Additionally:
@14degF - 7K to 12K ohms
@70degF - 2K-3K ohms
@180degF - 270-300 ohms
I know I'm kicking a dead horse here, but was it in spec? If you're saying it was 2200 ohms @ 70degF it'd be good.
The IAT range is the same on pins 4&5 of the AFM connector.
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Okay thanks a lot for the help Dave, I do appreciate it! Ill check it Sunday when I get back in town, and let you know what I see. Thanks again
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Okay well we did the testing, Cam sensor was 1200, and crank sensor was 510. I read A few threads, its saying that its +/- 10% which would be like 580-700 range. So I think were going to order one and see what happens. Because 70 OHMS under the minimum is a lot.
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I've read a few instances where people were getting bad aftermarket sensors. Might be best to bite the bullet and pay for BMW parts in this case.
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I've read a few instances where people were getting bad aftermarket sensors. Might be best to bite the bullet and pay for BMW parts in this case.
Yeah same here, its about 120$ for a Bosch so thats what we are going to do. It must be a hot item, only place i could find one was turner and bavauto. Pelican is out of stock like most other places.
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http://www.m42club.com/forums/showthread.php?t=13509&highlight=crankshaft+position+sensor+specs it could also be something similar to this?
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Also forgot to mention, the car has about 5 stripped out bolts on the VCG, was reading some info that it could cause PCV vacuum leak, causing it to fail, thus throwing a CEL for o2 sensor because it allows to much air in and dilutes the AFR causing it to run rich in conclusion it runs like shit and throws a 1221 code..All started couple months after the VCG bolts were stripped. Here is the link. Thanks
http://bmw.e30tuner.com/articles_vchc.php
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Also forgot to mention, the car has about 5 stripped out bolts on the VCG, was reading some info that it could cause PCV vacuum leak, causing it to fail, thus throwing a CEL for o2 sensor because it allows to much air in and dilutes the AFR causing it to run rich in conclusion it runs like shit and throws a 1221 code..All started couple months after the VCG bolts were stripped. Here is the link. Thanks
http://bmw.e30tuner.com/articles_vchc.php
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Anybody?
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So I put a fuel pressure gauge on it.. So when i turn the car over its not pumping fuel very fast i have a clear line off the T valve thats on the fuel line, so I can actually see the fuel coming up the line takes about 15-20 cranks for fuel to reach gauge. Will start after that. idles perfect at about 32 psi now when I go to drive it this is what happens. Car at this point is at running temp ~175-180 im in second gear( does not matter does it in all gears, even neutral, psi drops faster with a load on it) cruising at 2K rpms fuel pressure is ~30 the more gas you give it the faster the psi drops until it is at 0 and has no spark you can pump the the pedal and have no response. But if you let off the gas the pressure jumps back up to ~30 psi.. So basically its when you give it gas that the PSI will fall to 0... Any thing I can check? fuel pump is about 5 months old, same with filter I replaced them at the same time.
HERE is a video, kinda crappy sound due to my Lifeproof case.
http://www.youtube.com/watch?v=MNF7GRzX4f0
As you will see when fuel pressure is at 30 im barley on the gas ( more so momentum than throttle) as you see it drop I am giving it a range from 50-100% throttle, basically the more you give it the faster it drops to 0 and has no spark. Let off throttle goes back up to 30 psi..Thanks for looking!
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I couldn't really tel what was going on with the video. Maybe check the fuel pressure regulator? I'd guess if it was broken it might be letting enough fuel past that the pump can't keep the pressure high enough? Is the FPR vac line secure to the TB?
I'd also check the fuel pump relay, sometimes the coil gets weak or the contacts wear out. I'm pretty sure it can swap with the wiper relay.
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Alright I'll look at the relay, it has the same exact one for the fuel pump and the o2 heater. I tested resistance on pins 86 and 85 they were both 84.8 ohms so idk if that's good or what. But like I said I have a clear tube off the T and you can see fuel as it cranks and barely goes up the tube like its using the oil pressure to pump fuel. But in the video it has a constant 30 psi but when you give it gas it just drops out to to zero if you keep on the throttle..
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http://www.youtube.com/watch?v=NcaD2oRjb4s
So this is odd, car is running and has 0 PSI... anybody? Im stumped, only thing I can think of is stuck open fuel injector. Exhaust is strong and squirts out fuel..
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http://www.youtube.com/watch?v=NcaD2oRjb4s
So this is odd, car is running and has 0 PSI... anybody? Im stumped, only thing I can think of is stuck open fuel injector. Exhaust is strong and squirts out fuel..
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Hmm. Never tested a relay for resistance before. I'd suspect the switch side (85& 86) would be a pretty small resistance, but the load side would be infinite, at least for a standard always-off SPST version.
The FPR does vary the fuel pressure based on intake vacuum - but your problem seems like a flow issue. That pump seems a bit weak regardless...IIRC 43.5psi (3bar) is minimum system pressure for the M42.
Put a hose on the fuel pump and run it to a gas can. With the key on and the fuel relay socket jumped (or 12VDC on the fuel pump terminals), Bentley says you should see nearly a quart every 30 seconds. That's be a gallon every 2 minutes. With this test you can eliminate the entire supply system and isolate the fuel pump for testing.
If this test succeeds, then maybe a blockage in the system? Crimped fuel supply or return hard line, internally collapsed hose, blocked filter, plugged pump sock, something like that?
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AHHH, Finally its FIXED!! It was the power connector to the fuel pump was busted, so it would not stay on the prongs. The "fuel cut" i was experiencing was the connector going from making contact to not and would kill the pump and come back on. Wow am I glad thats fixed now to find a new plug somewhere. Thanks to everyone for the input!!
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Here is the plug.