95 barely runs need help

[islandtime]

I picked this project up and its starting to baffle me. I've had a few E30 M42's but this is my first E36. It starts when cold but still has a rough idle and quickly begins to bounce from 500-1200 then slowly goes down till it shuts off. If I hit the gas it will stumble and generally shut off but sometimes revs up but slowly comes back and shuts off. I can tell there's an exhaust leak and I suspect a clogged cat but I'm getting flow out the exhaust so I feel it should still at least idle. The previous owner replaced the fuel pump, fuel filter, TPS, AFM, IACV and I've replaced the CTS, coils, plugs/wires, and now the cam sensor and no real change. The intake boot is also new and so are all the intake manifold gaskets. I can't find any vacuum leaks and most of those hoses have been replaced as well. It doesn't just sputter out either, when it shuts off its like a misfire because it stops abruptly and violently. I tested the crank sensor and it ohm'd out to what I could find online but the cam sensor did as well but it ran just the same with the sensor pulled out and hanging as it did installed and it didn't even throw a code for anything yet. When I pulled the plugs they were all four equally carbon fouled so I know its not just a sticking injector, unless all four are stuck open but they ohm out right as well.

[318iM44]

Get the CEL scanned, and start with the easiest and cheapest fix.

[islandtime]

Did you even read anything I wrote? I'm not trying to be a dick but your response tells me nothing. I already said it hasn't thrown a code. I've done the stomp test and my peake scanner and no codes at all.

[318iM44]

Originally Posted by islandtime

I picked this project up and its starting to baffle me. I've had a few E30 M42's but this is my first E36. It starts when cold but still has a rough idle and quickly begins to bounce from 500-1200 then slowly goes down till it shuts off. If I hit the gas it will stumble and generally shut off but sometimes revs up but slowly comes back and shuts off. I can tell there's an exhaust leak and I suspect a clogged cat but I'm getting flow out the exhaust so I feel it should still at least idle. The previous owner replaced the fuel pump, fuel filter, TPS, AFM, IACV and I've replaced the CTS, coils, plugs/wires, and now the cam sensor and no real change. The intake boot is also new and so are all the intake manifold gaskets. I can't find any vacuum leaks and most of those hoses have been replaced as well. It doesn't just sputter out either, when it shuts off its like a misfire because it stops abruptly and violently. I tested the crank sensor and it ohm'd out to what I could find online but the cam sensor did as well but it ran just the same with the sensor pulled out and hanging as it did installed and it didn't even throw a code for anything yet. When I pulled the plugs they were all four equally carbon fouled so I know its not just a sticking injector, unless all four are stuck open but they ohm out right as well.

Originally Posted by islandtime

Did you even read anything I wrote? I'm not trying to be a dick but your response tells me nothing. I already said it hasn't thrown a code. I've done the stomp test and my peake scanner and no codes at all.

I could've read it better if all of the information listed were in a little better paragraphed.

If there is zero vacuum leak, is there a chance that one or two vacuum hoses accidentally cross swapped?

[islandtime]

Not much of a chance. There's one to the fuel pressure regulator, one to the booster, one to the evap canister, and one to the pcv system. Kinda hard to mix those up. Sorry for running on earlier, it was alot of information to get out in hopes people would know what has already been done and not waste time suggesting things that have already been done.

[teetime4one]

Have you cleaned the ICV? Brake cleaner seams to be the ticket.

[islandtime]

It's a brand new valve. That wouldn't really explain why it won't run though, just a bad idle.

[318iM44]

As you said all of the (good condition and correct specs) spark plugs are carboned up, i think the dme is trying to dump excessive fuel more than it supposed to.

It could be the O2 sensor is reading way below the threshold, so the dme is taking it as the engine is running too lean and trying to enrich the fuel mixture.

[islandtime]

That's a good point. Will it dump that much from a bad O2 sensor? I've had them run a bit rough but this is so bad its like the injectors are just held wide open all the time. Funny thing is the other day it started up and idled fine for about 15 seconds, just a bit rough and took throttle if I babied it. That got me in the garage but it hasn't run more than a few seconds since. I changed the plugs to some new ones just to check that and no change there either. I'm gonna pull them and see if they're still running that rich. I'm gonna pull the injector plugs and see if they're just grounded and staying open the whole time. I have heard the DME's rarely fail but that's the end of a long list that's getting shorter as I'm running out of parts to change.

[anthony318ti]

Funny thing is i cant seem to find an O2 sensor on my 97 Ti M42, car used to shut down while driving but not instantly a gradual power loss till off, sometimes starts dies out, rough ide bouncing every where. My issue was the barn gate on the MAF sticking. By cleaning the walls and sanding it down a bit that solved part of my issue apart from the idling. So i opened it up and readjusted it and it was perfect. Here is a youtube video i made hope this helps buddy. http://www.youtube.com/watch?v=MTnB5X4lURk&feature=plcp

[islandtime]

I've got 3 AFM's that I've swapped back and forth and no change between them so I'm pretty sure it's not the AFM itself. All three move smoothly and one is even brand new. I'm also thinking my FPR may be stuck shut and jacking the fuel pressure as well but I haven't verified fuel pressure yet. I have to rig up a t fitting to hook my gauge into first.

[anthony318ti]

Originally Posted by islandtime

I've got 3 AFM's that I've swapped back and forth and no change between them so I'm pretty sure it's not the AFM itself. All three move smoothly and one is even brand new. I'm also thinking my FPR may be stuck shut and jacking the fuel pressure as well but I haven't verified fuel pressure yet. I have to rig up a t fitting to hook my gauge into first.

Im out of ideas. Sorry bud. It says your from Hawaii must be nice there Hope you get it fixed soon.

[b.u.ti-ful]

Where is the exhaust leak? I would fix that first.

[anthony318ti]

Does your injectors click power test? i just read your post again when it ohms out just means that there is continuity as you already know maybe a power test? click click click

[islandtime]

I can't really be sure since it won't run long enough. I just hear it sometimes, like a pop from under the car when it shuts down. I'm running out of ideas as well, I've been a mechanic over a decade and raced quite a few bmws but this one is driving me nuts. My last M42 E30 gave me no real problems in 80k miles and numerous trips to the track. And living in Hawaii is nice but getting big parts is very expensive, I got lucky and found an M3 in a junkyard and took the side skirts and bumper for $80 but that's rare.