[isoulride]

I've been doing some reading on the forums and have found some info about what might be happening, but haven't been able to find someone with this exact problem. Here's the question.

I bought the car about three years ago, it has an aftermarket cold air intake, and the check engine light has been on since I've had it (it ran fine, so I figured it was just aftermarket components messing with the OBDII system). Just recently I've had an issue with it starting up every once in a while. It always happens after I've been driving it for a while (at least 45 min) when I shut the car down to go into the gas station to get a drink or something I try to restart the car and it fails to start up. The first time I turn the key it fires, but the RPM's don't go over 600 and it just sputters out slowly (won't stay running for more than 30 seconds) then if I try to start it again it will fire again, but this time it won't even go up to 600 RPM's. If you try to start it enough times it'll just not fire. First time this happened to me I had my Dad come and help, he was coming from about an hour away, and when he got there I tried to start the car and it worked fine. Since then it's happened two more times, and every time if I let it sit for about 30 minutes it will start up normal. I've taken the car into autozone to get the codes run, and it just says the car is running rich on both sides, no specific code about any sensors or anything...

So a summary:
1. Engine has to be hot
2. Car is turned off for about 5 minutes
3. Upon restart the RPMs sputter at 600 and slowly die
4. 30 minutes after the problem is gone

[shinerstang]

Check your IAC. It is most likely the culprit. If it is not telling the computer the temps, it cannot adjust accordingly.......

[isoulride]

I've done some googling and it does indeed sound like the IAC valve. I've also read that "cleaning" it is only a band-aid and the problem will most likely return. And that it's not a good idea to buy a used one from a junk yard since it's a "wear" component. So my question is, can you tell if the valve is bad by checking resistance, pull-in, drop-out, visually, or anything like that? I would like to confirm the valve is bad before I drop a hundred dollars into a new one. Since it's an intermittent problem I might not know if it's still not fixed for a while.

Thanks!
Dave