Daniel Male Hicks

I Bought a 94 mustang 5.0 with GT40 heads, I believe E303 Cam, trick flow intake, BBK 70MM throttle body, 24lb injectors, and some other odds and ends.. the last time the car was idling right is when it had 42lb injectors (had a super charger) but since I have went down to the 24's I can't get the car to idle... it will jump up to 3k then go down to 500 then stall.. or will go to 800 then right down to 500 then stall... if I hold the gas it will hold erratic rpms.. please help

TrimDrip

you need a tune. the ecm still thinks you have 42lb injectors.

wbrockstar

Were you running an aftermarket maf sensor calibrated to 42lb injectors & are you running that same maf sensor with the old injector (42lb) calibration or did you keep the stock maf sensor and do the injector calibration in the ecu via a chip?? You would need one or the other when moving from the stock injectors,unless you've got an aftermarket ecu system.If you were running the combo in the post above,minus the supercharger,and using the stock 70mm maf sensor with the stock 19lb injector calibration in the ecu and you swapped to 24lb injectors,they would trigger a slightly rich condition since more fuel is gonna get thrown at the engine because the 24lb injectors running at the same pulse width as the 19lb injectors will pump more fuel to the engine.

mjr46

as stated make sure the maf is "calibrated for 24's" and no vac leaks exist, and if those two issues are not issues, then do a KAM reset/base idle reset