Hello, before I get flamed I did try the search function first. Ok. I have a 1987 S10 with a 2.5 4cyl and a manual trans. When I start it, it immediately starts to idle higher than heck. It will not idle down at all. The previous owners put in a new trottle position sensor. No change. Also no check engine lights. Does the Idle Air Controller affect idle that much? I don't know what else to try. Any help or tips would be greatly appreciated. Thank you.