Originally Posted by carta79
Idle control system malfunction.
Possible causes:
IAC valve mechanical malfunction
Fast idle thermo valve malfunction (A/T)
Throttle body clogged port, improper adjustment
Intake manifold , gasket leakage
Intake air hose loose, leakage
Vacuum hoses leakage (already stated)
ECT sensor
Throttle position sensor incorret output
If you don't have an automatic eliminate the Fast idle thermo valve as a possible cause.
I was figuring it was a radiator problem because of where he noted steam in the engine bay. If air got into the system through a leak in the radiator, it could cause his funky idle.
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2015 Ford Mustang GT Fastback - Ingot Silver - 6M - Performance Package - Gibson Catback, JLT CAI, FR 47lb injectors, BAMA E85 tune, Eibach Sportline, BMR wheel hop kit, UPR oil separator, Steeda shifter bushing/bracket
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