I don't think the IAC valve can let any unmetered air into the engine, so it shouldn't have any effect on normal running conditions. Even if it is unmetered air, the amount the IAC valve is capable of allowing in shouldn't have anywhere near the effect on the engine that you're experiencing.


95 Montero SR
3.8 MIVEC, Advance headers, 2 1/2" exhaust, Magnaflow muffler, OME shocks & rear springs, 2" body lift, 3" tank lift, 4.90s, TRE front locker, factory rear locker, Roger Brown Rock Sliderz, 315/75r16 (35") tires, Sport big brakes