1991 E30 325is M20 running super rich/ idles just fine

[invertedgeek]

Hi folks,

I have been a long time lurker in this forum, desperately need help to get this baby smogged, any inputs would be greatly appreciated!

The main problem is that it is running very rich (blowing huge white smoke which smells like fuel upon revving. It stalls especially easily during cold start.
However, once the car is warmed up, idling is very stable and smooth.

Recently replaced:
OEM New intake manifold gasket
OEM throttle body gasket
OEM New injectors
OEM Spark plugs
Performed smoke test multiple times, no visible leak from any vacuum hoses/ intake manifold gasket.

I used Autologic scanner (DME) and two fault codes were shown:
(022) 16 Idler actuator
(010) 0A Oxygen Sensor Control

I did research and could not find any information with regards to these two codes, regardless, I went ahead and replace a new O2 sensor. Cleared code and ran the scanner again, the only code left is (022) 16 Idler actuator.

I guess my question is, is a bad Idler control valve really makes the car running rich? Additionally, I tried disconnect the idler control valve sensor while the car was running and there was no difference in idling whatsoever. What else could be the problem of it running super rich? I would appreciate more opinions before I spend another $170 for a new idler control valve :(

Thanks for your time!

[MrBurgundy]

If you unplug your icv and nothing happens, that or the tps have taken a shit.

But iirc if you unplug it and nothing happens, the tps is shot, and when that doesn't send the dme a signal the idle control valve stays wide open.

try doing a stomp test and see if it works, thats a quick way to check if the tps is working. You could also do a continuity check. If you don't know how to do those, search

[digger]

Also if the ICV is not open far enough during cold running it might be possible for it may run a bit richer but it would like idle lower to. if its throwing a code id replace it as even if not the issue you eliminate potential issues down the line

white smoke is often coolant getting into the combustion chamber assuming its not just normal condensation

[invertedgeek]

If you unplug your icv and nothing happens, that or the tps have taken a shit.

But iirc if you unplug it and nothing happens, the tps is shot, and when that doesn't send the dme a signal the idle control valve stays wide open.

try doing a stomp test and see if it works, thats a quick way to check if the tps is working. You could also do a continuity check. If you don't know how to do those, search

Thanks for your advice man!
I tried doing a stomp test but it didn't work because the red check engine light stays on forever without blinking at all whatsoever. I am away from the car right now, will try to do the stomp test manually under the hood tonight and see how it goes.


Question: Any other way to perform the stomp test? Thanks.

[MrBurgundy]

Thanks for your advice man!

I tried doing a stomp test but it didn't work because the red check engine light stays on forever without blinking at all whatsoever. I am away from the car right now, will try to do the stomp test manually under the hood tonight and see how it goes.





Question: Any other way to perform the stomp test? Thanks.

That means the tps is bad. The stomp test is initiated when a signal is sent from the tps


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[M_3_X]

Have you checked compression just in case?