m50 stalling at idle

[EtaSport]

So twice now after the car is fully warmed up Ive come to a stop and the car has died when pushing the clutch in. Its had some idle searching problems ever since I put it in. Much like an m20 with anything other than a 173 ecu where it keeps going down then bumps back up.

After it dies both times I've started it back up and it quits again. The second time I give it some gas an let it idle down slow and it will idle okay, still not great.

I think there may be an o2 problem which may or may not be part of this mess because I had a lambda code present as well as a knock sensor code. Is a bum o2 sensor known to cause issues like these?

[Brew]

Is a bum o2 sensor known to cause issues like these?

For sure. I'd just throw a new one in, especially since you have a code.

[matt]

Sounds like a vaccum leak.

[FredK]

I'm having this same problem with my m42 right now, it started just a few days ago.

I don't understand why it'd be the O2 sensor; the engine doesn't go into closed loop operation until it's pretty warm, and my troubles are pretty much when the car is stone cold. Any body else?

[quan325i]

It sounds like you have a leak. When it's cold, rubber tends to shrink exposing vacuum leak. Check your air boot near the AFM.

[SchnellerVert]

ICV dirty. They are a pia to get to. Quick check is your MAS unplug it see if it doesn't shut down. Cone filter? Dirty sensor.

[FredK]

Gonna have to bust out the propane! Thanks guys.

[Brew]

Idle control valve could be the culprit in your case Fred.
I would try cleaning it out thoroughly with some carb or brake cleaner.

[trent]

IF you are running a LTW flywheel this could also happen just because the chip can't compensate for the mass. My car with the 8lber dies about once a day...no big deal.

[FredK]

This M42 is pissing me off. My car's such a POS but I'm thinking of doing an M50 swap just for fun. Personally I'm using a HMF flywheel. Heavy Mo' Fuggin flywheel. Drop it on your toe, and you might have to amputate.

I'll try the ICV.

[EtaSport]

It can't be a leak because it only happens so often. Its usually only after a long highway drive and coming to a stop. Then if I blip the throttle and the rpms want to come down, it just keeps going til it cuts off.

Stock s50 dual mass flywheel, so no problems there. I am thinking it could be the ICV or also the hfm because I do have an oiled filter. I want to get the o2 sensor squared away though so that I have no codes.

My roomates e30m50 had some bouncing idle whenever his o2 sensor flashed a code.

[SchnellerVert]

Did you disconnect the HFM? Drive it in the same way and see what it does. There is an HFM cleaner out there now that cleans the element.

[Mot]

Mine used to stall at idle because the battery was poorly grounded and the dme wasn't getting a clean constant 12v. The motor would slowly rev down, then sputter and die.

[SchnellerVert]

Weather was rough out your way did you get it ironed out?

[bmws50b30]

IF you are running a LTW flywheel this could also happen just because the chip can't compensate for the mass. My car with the 8lber dies about once a day...no big deal.

i have this problem but never thought it would be flywheel realated. it did start after i replaced my tranny and installed JB racing flywheel.

my car would stall coming to a stop, after i shift to neutral. i would pop the clutch and it starts right up. i still have this problem but i haven't get the chance to clean the icv yet. my car would stall 3-5 time a day.