tp sensor maybe...my friend is having the same problem..with his stock intake...runs fine until it gets up to temp then it idles up to 3500!!!

i cant figure it out we changed the iac,nothing found a bunch of loose hose clamps from the new clutch install...still didnt help...i did run into this problem with pre98...i installed a 60mm tb on his car and it had a similar idle problem...come to find out the tp sensor was bad...might be it , might not....