92 325i Intermittent Hesitation/stalling when hot

[vwvannut]

Alright, here's my old problem that i can't seem to solve. I've got a problem with low rpm hesitation, and sometimes stalling.

Symptoms:

Hesitation when starting out in any gear, particularly prevalent in second gear, sometimes resulting in a complete stall.

I can usually make this happen by giving the car half throttle at around 1.5-2k rpms. Once above 3-3.5k rpm the car runs fine.

During hesitation i can feel the car "tapping" or pulsating almost like the antilock break feel, but obviously on the gas.

Again this is intermittent, but rarely does it occur in cooler conditions, in warmer conditions, high 80s and up, it will occur regularly though still somewhat intermittent.

When cold the car idles around 1.5k and when applying the brake the idle jumps wildly between 500 and 1.5k until the car stops then it is fine. (I can't find any vacuum leaks)

I've changed the plugs, crankshaft position sensor, o2 sensor, and both coolant temp sensors, as wells as swapped out the mass air meter, and TPS. Fuel pressure is about 4psi too high, but i don't think this would make to much of a difference. Also the OBDI for the 92 325i does NOT have all the features that the 93 and up have. It won't tell me about the coils, injectors, and many of the sensors, really just the emissions related items, o2 sensor, mass air, etc. I have does all the bentley tests on the coils and they are within spec.

Any ideas????
Thanks

[downeaster1]

Idle air control valve, coil packs and injectors. It did the trick for my 92'

[vwvannut]

Did you have the exact same hesitation problem? I was thinking the coils, but they check out on the resistance test in the Bentley. Like i said i'm stumped.

[Doug001]

Did you have the exact same hesitation problem? I was thinking the coils, but they check out on the resistance test in the Bentley. Like i said i'm stumped.
You can't (and shouldn't) trust the resistance test on those coils. They can test good with a meter and still be farked. If they've never been replaced, then you really ought to get new ones. Not another set of old used ones, either... :nono

Additionally, I recently had a very bizarre idle problem with my '92, and it turned out to be the Idle Control Valve - my mechanic (a swarthy eastern-European transplant) referred to it as the Idle Motor. It wasn't dirty, the windings inside were intermittently open. The only code I got was a bad throttle position sensor (which turned out to be just fine, thank you).

So, to reiterate, coils and ICV. If the injectors haven't been serviced/changed, then they should be looked at as well.

Luck. :D

[vwvannut]

Excellent finally some people who understand us the 1992 bastard child. Two of the coils have been changed, the others show 1991 as the year of manufacture so i'm sure they are original. Might as well change all of them. thanks