Running a 350 Vortec with 454 throttle body on engine stand. There appears to be another item that needs fixing. After some number of minutes running, an IAC fault is set. The pintle appears to be nearly fully extended position. Don't know how the 16197427 $0D ECM sets this fault or what is setting it. After shutting down, the pintle appears to be fully retracted. Need suggestions as to what to do for this IAC situation.