I have a Sunfire 2200 2002
I was driving through a parking lot one day at almost 5000 rpm and the second I let off I went to pull up to a stop and my car stalled. I started it and it would only start with WOT. Since then the car would not idle unless my foot was on the gas. So then I started replacing parts.
I replaced with the the IAC valve, after an attempt at cleaning it solved nothing. It started the first time, revved very high, and stabled out to idling at 1000 rpm (this is a manual car).Great I said, Then I shut the car off, and then attempted to start it again, it then did the same thing, wouldnt start unless I had it WOT.
I was baffled, and since then, Ive changed the throttle body, the injectors, the fuel rail, pressure regulator, spark plugs, wires, both coils (not the plates). Still with no luck. The only way I am able to run the car is if I have someone start the car, while I manually throttle the gas from under the hood, I push in the IAC valve with a screwdriver untill I dont need to give the car any throttle, I then unplug the IAC valve. It's the only way im able to run my car for the time being. I only have a miserable time to get it going in the morning since where I live its -25,

I read a few placed on the internet of a guide to reset the IAC valve by disconnecting the batterty, then plugging in the IAC valve, KOEO ffor 5 seconds, then key off for 10 seconds, then it should start and idle as its suppose to. Tried it, didnt work. To me it seems to be whatever is controlling the IAC valve, which would be the PCM most likely.

If anyone has any input that may help me it would be very much appreciated.
Duke