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....

"Youth ages, immaturity is outgrown, ignorance can be educated, and drunkenness sobered, but STUPID lasts forever."-Aristophanes. --93 pgt,headers,intake,borla=14.9 1/4mile