Well I have a 92 T/A with 99K miles. I recently finished installing edelbrocks hi-flo base and runners, along with their headers, and a cat back exhaust system. Also replaced the injectors with ford injectors and installed a afpr. The idle is off a little. It jumps from 550 to 600 and every once and a while it drops a little lower then that and feels like it's going to die but doesn't. I took off the IAC valve and cleaned it. I tried to adjust it but to no avail. It would not move. Not sure if I was doing it wrong or if it is damaged. How do you tell if the IAC is still good or not? I replaced the cap, rotor, and wires already. Thanks for the help.