Check your vacuum connections. Check the cam timing. Did you replace the gasket when you put on the new IM? Did you properly bleed the coolant system when you swapped, and after you changed the IACV?
__________________
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
Team B.O.B.® - Ballaz on a Budget