hey guys, i got a erratic idle problem. when it's warm and i rev it up high long enough when i get back to idle pass from 750-1250 rpm continuasly till it finally stop and rev at about 900-1000rpm. i screwed the fast idle valve to it's maximum clean the IAC chek my O2 sensor signal visually inspect vaccum. but i'm saying to myself that it can't be vaccum since it only does it when warm and under load condition. the engine is in very good condition(compression oil pressure valve clearance etc.....) so my next idea would be to make sure ECT work properly. when i unplug the IAC when there's erratic idle the idle gets back to 750 steady. but under driving condition it's pretty hard to go without a IAC!!!!! so could anyone help me out or suggest me some idea that i haven't though of. thx guys appreciate!