Erratic idle and stalling

[AXLE]

I have to feather the throttle when stopped in traffic, it will stall if I don't. Also I have to open the throttle to start it, and it also feels like a very breif stumble on the highway as I ease off the throttle. No codes are stored, the CEL is not on. I replaced the IAC simply because I wound up with a new one on the shelf, it made no difference. Also I swore I could hear a vacuum leak at the intake, sprayed with throttle body cleaner and got a better idle at one port, so I changed both the upper and lower gaskets, no difference :cry: .

And the motor only does this when fully warmed up to operating temp, when it's cold and as it warms up it seems normal.

What do you guys think I should check or test? Is there anything else you need to know? TIA. :usa:

[03Alerosil]

It may be a fuel related issue.

[sleepyalero]

Sounds like a bad IAC valve.

[AXLE]

Sounds like a bad IAC valve.

I agree, that's why I replaced it.

[sleepyalero]

Whoops, didnt see that in the original post, my bad.

[sleepyalero]

This is a tough situation, you really may just have to take it somewhere to be diagnosed....

[Redog]

IAT sensor wires still intact?

My car did some of that stuff and I found both wires broken off the sensor ;)

Could also be a MAF. They are a bitch when they go out. Try cleaning it first. Sometimes those wires get crudded up real good. I wouldn't use anything but MAF cleaner either.

[03Alerosil]

This is a tough situation, you really may just have to take it somewhere to be diagnosed....

I agree with you sleepy. I thought IAC as well. Even had a suspicion of a bad torque converter. The car needs some data ran on it while it's trying to stall so you can see what's going on.

[AleroB888]

I have to feather the throttle when stopped in traffic, it will stall if I don't. Also I have to open the throttle to start it, and it also feels like a very breif stumble on the highway as I ease off the throttle. ...........................And the motor only does this when fully warmed up to operating temp, when it's cold and as it warms up it seems normal.



You could scan it from cold to hot as it warms up, and observe if the problem occurs when the PCM goes from open loop to closed loop. The MAF sensor (and O2 sensor) take over fuel trim management at that point.

[[ion] C2]

IAC/TPS/vacuum

for sure