Stalling at stops

[blk92z34getrag]

My car has a really odd problem...

Whenever I come to a stop (i.e. speedo @ 5 - 0mph) the idle drops really hard, and sometimes stalls. Mind you my car is a 5 speed and this happenes wether I'm holding i the clutch in gear, or put it in neutral as I come to the stop.

It sort of seems like it's trying to drop the idle like it would in an Auto... which made me think these guys bought an auto ECM (the one in my car right now isn't the original, it says "remanufactured by GM"). Could this be the problem? Or is this just the infamous stalling problem I've heard a lot of people have?

The IAC valve is new (in case anyone thinks that's it).

[SappySE107]

It could be the BCFA chip, but that was the one that is supposed to fix the stalling issue. Only other known problem is the thrust bearing wearing out...but I dont think it would want to idle any time if that were the case.

[blk92z34getrag]

BCFA chip?

I got the FFP chip a while back (don't know if that chip is the BCFA chip) and that helped the erratic idling somewhat (set it to idle at 800 I believe), it either idles, or it dies... but it does drop everytime I come to a stop, sometimes more than others. Sometimes when it bogs down to almost stalling (~200RPM) it will suddenly jump to 3000.

EDIT: Also what is the thrust bearing? is that the same as the throw-out bearing? Because I think my t/o bearing is chattering and starting to take a crap on me.

[SappySE107]

No, the thrust bearing is part of the main bearings, and is what keeps the crankshaft from walking. The 5 speed is hard on it, and was cause for problems but I am unsure what GM did about it.

The FFP chip is BCFA based, so that wont be it. It does sound like the IAC isn't open enough when coming to a stop, and sometimes it is able to react im time. Gotta love GM tuning, yet something has to be wrong since now every 5 speed does this. I have no problems at all.

[blk92z34getrag]

I'll try taking the IAC out and check if it needs to be cleaned... I'll try cleaning out the throttle body there too.

I love these cars... but damn their problems!

[SappySE107]

Carbon in the IAC hole itself can be a real PITA, but blasting it with carb cleaner works well. Q tip will help as well. Your problem may be a vacuum leak as well. How is your brake booster hose doing? Probably not related but you never know.

[blk92z34getrag]

Actually when I bought the car it had just generic bulk hose going from the booster to the upper intake, I replaced it with a new OEM hose, so it's new.

I just shot it up and ran a towel through the hole... I had it idling for about 5 minutes with no problem. Revved it a few times (pissed off my mom, she was watching T.V. ) and it didn't attempt to stall at all. I also tried running all the accessories (stereo, vent, signals, brights, everything) and it was fine. Gonna go take it for a spin right about now and see how things are.