Contour Enthusiasts Group Archives Forums General Troubleshooting wont idle!! and when it does its at 250 RPMs

My car wont idle. The RPMs just fall all the way down to zero. After it was warm the car was sometimes idling at 250RPMs. yeah 250 not 2500. It started not idling on occasion in the winter, more than once i was under the hood playing with the throttle and then i heard a weird popping, or clicking sound and then it idled like normal. I do have a CEL, dont know what it says but will have it checked tonight. There is no longer cold weather obviously and my car has been down for a month. i just got it running and it either idles at 250 or not at all, should i reset the PCM? new IAC? check for vacuum leaks??

I'd say you have a sticky IAC. The clicking that you heard before when it returned to normal idle was probably the valve popping back open. Some of the other folks will probably better diagnose this... but it would be my first guess.

well that seems to be easy enough, so i just clean this bad boy up and we are ready to roll??? so where exactly is it??

it is a small aluminum-looking cylinder coming off the rear right side of your UIM. Take it off and use some TB cleaner on it. If that doesn't do the trick, new IAC's are only about $60. I'd try cleaning it first though.

Even if you just take it off and clean it, put a new gasket on it before you put it back on.

quick update... i cleaned the IAC, bunch of nasty black stuff came out. well the car idles now... but only when its warm. When the car comes up to temp it idles at like 500-750 range, which i feel is acceptable, but it still stalls out anytime the gas isnt applied when its cold. I tried using starting fluid looking for vacuum leaks. No luck there. But i did notice one hose that runs behind the motor that would move when i reved the engine. i was going to snap a pic of it, but cant find my digi cam. also, didnt put on a new gasket on the IAC because i didnt have time to go get one and didnt know where to get one. so, any other thoughts??

IMO cleaning parts that are acting up does little to nothing. It's a 30-40 part just replace it.

I'm having the same problem. At times it won't idle at all, at times it tries to idle at about 500 rpm or lower, at times it idles at a very fast 1500-2000 rpm, at times it searches back and forth, going from 500 to 1500 rpms. Here's the kicker. I replaced the IAC only a couple of months ago. New IAC, new gasket, and it still won't idle. I can't find a vacuum leak. The problem is worse when the engine is cold. After it gets warm, it will usually idle, although the speed is too fast, and it still revs up and slows down. I'm suspecting a computer problem, although I've reset it twice, and it didn't help.
Maybe the vss or crankshaft sensor are involved somehow.

Might be a MAF or TPS issue.