85 eta rough misfire black soot from exhaust

[crazyman]

You have almost the same issues as what I just fixed and it wound up being bad gasket/loose bolts on the cold start injector adapter to the intake(the piece that the cold start injector bolts to). Hope that helps.

[2.5-12]

You have almost the same issues as what I just fixed and it wound up being bad gasket/loose bolts on the cold start injector adapter to the intake(the piece that the cold start injector bolts to). Hope that helps.

good to know -- another vote for vacuum leak.

did your car take a bit of cranking on cold start?

[crazyman]

Yes it did, alot. Tried to give a tiny bit of throttle to help and the system freaked an almost flooded it. So after that I said f***it and just let it crank till it caught.

[2.5-12]

haha, yep. mine will actually briefly hydrolock with all the fuel, then start cranking again -- then I get thick white smoke out the back for a few seconds while the cat burns off all of that fresh fuel.

hmm, I am going to probably just order a full set of intake gaskets and o rings and just do it anyways. but I'll start with that small one :p

[crazyman]

Cool, glad I could help.

[2.5-12]

ok, skinny scoop guys

I got my 325i out of the shop and rolled this bad boy 325e in there.

decided 'fuck it' and just did all of the gaskets on the intake manifold, all of the hoses, new clamps etc.

while I was at it, I decided to eliminate the variable of the intake manifold, TPS and TB since the old manifold had a suspicious crack in a potentially problematic area.

started it up....

no change. still revs really nice. idles fine (but at about 900rpm) cold start injector plugged in or unplugged, makes no difference.

still getting wet black soot out of the exhaust when I rev it.

starting to run out of things to try short of converting this thing to Motronic 1.1 SETA electronics.

fuel pressure is 30PSI at idle and when off, rises to 37psi when revved which is right within spec.

[2.5-12]

I pulled the injectors/fuel rail out and jumped the pump just to make sure they weren't seeping and everything checked out a-ok there too.

they don't leak.

anything else to check/do? there's practically nothing left on this car to change.

[dnguyen1963]

Well, if you still get black soot then your car is still dumping way too much fuel into the system or you still have a big vacuum leak somewhere. What type of injectors do you have? I would remove the injectors then hook it up to a battery and check to make sure that fuel is being delivered correctly (google the procedure). I have seen injectors shooting straight stream of fuel without any spraying pattern.

[2.5-12]

Well, if you still get black soot then your car is still dumping way too much fuel into the system or you still have a big vacuum leak somewhere. What type of injectors do you have? I would remove the injectors then hook it up to a battery and check to make sure that fuel is being delivered correctly (google the procedure). I have seen injectors shooting straight stream of fuel without any spraying pattern.

standard ETA low impedance injectors. 0 vacuum leaks since i just sealed everything.

just replaced what I think was the DME temperature sender (orange new) old was clear.

occasionally when restarting after stalling, it does seem like it is hydrolocking on fuel temporarily but its hard to say.

I do somewhat suspect injectors but I just replaced pintle caps and o rings and everything looked good. but I did not test spray pattern (have been trying to avoid it). just seems odd that the car ran perfectly before all the maintenance stuff.

[dnguyen1963]

If you think you have hydrolocks then too much fuel is being dumped into the cylinders. Rebuild the injectors or buy a new set. Pintle caps and o-ring alone are not enough if your injectors are not spraying correctly.

[SlamedIAm]

0 vacuum leaks since i just sealed everything.

Have you ran a smoke test to confirm this or are you assuming because you've replaced so many parts?

[2.5-12]

both.

I have replaced every gasket and hose in there as well.

[2.5-12]

If you think you have hydrolocks then too much fuel is being dumped into the cylinders. Rebuild the injectors or buy a new set. Pintle caps and o-ring alone are not enough if your injectors are not spraying correctly.

I am aware of that, but usually when the injectors are worn to that point, they are visually damaged when you're in there to change out o rings.

[dnguyen1963]

I am not convinced that you can visually inspect an injector. I have seen many that look normal, but will not spray or have abnormal spraying pattern. I have seen some with lagging fuel delivery, which can contribute to hydrolockings.

[2.5-12]

I am not convinced that you can visually inspect an injector. I have seen many that look normal, but will not spray or have abnormal spraying pattern. I have seen some with lagging fuel delivery, which can contribute to hydrolockings.

why does the engine behave properly under load if the injectors are shitting though? shouldn't that make it even more likely that they're working at least somewhat satisfactorily?

I'll buy a set from someone and rebuild them I guess, not a huge investment. or I suppose swap the entire rail from my daily to this car since that car runs as well as any ETA has ever run.