basically i have a poor mans type R motor and running with chipped P90.... problem is when my car is idling once in a blue moon RPM will jump up and down.... 700rpm~1300rpm.... just like when IAC valve goes out... but when i tap the gas once it will go back down to steady 700 idle..... help help help... why is my car doing this...? thanks for any help and have a great one guys~

 

im having the same issue.. did you figure out whats wrong?

 

I guess we need to know what 'chip' was used. Did it alter fuel maps, timing, EVAP crap or what.. Or is a just a chipped ecu w/ raised rev limiter, etc.
OH yeah, BTW, the F is a P90 ECU? Alittle naive on that specific application P90... that is all.
Absubtle
PA