i just bought this 1990 mustang GT that would push start because it needed a new flywheel, i replaced that and went to start the engine and couldn't unless i gave it gas. After that it would cold start and come back down and drive fine, it would turn on without use of the gas pedal everytime. But it happened again and i decided to clean the TB and the IAC, then the car would still only start if i gave it gas but it wouldnt survive at idle. So i replaced the IAC and now it still only starts with the gas pedal pressed but it wont come down in RPMs and die like it used to. Im stuck please help