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Engine Stalling and/or Hesitation on Acceleration due to Faulty Idle Air Bypass Valve on Ford Mustang

Problem Description and Possible Solution

If you experience difficulty starting the engine when cold, stalling at idle, or hesitations during acceleration, it may be the idle air bypass valve. This valve helps the vehicle idle steady when the accelerator pedal is not pressed.

Problem Data
RepairPal Verified
Average mileage: 115,666 (15,000–220,000)
3 model years affected: 1994, 1995, 2003
5 people reported this problem
Comments
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It is not fixed I have to start it at least twice in the morning or if it's been sitting for longer than a few hours and it dies after the first time it starts and then I have to start it again and it reeves kinda high then starts to try to bring its self down to idle and fights it's self to keep from dying again and will rev real high on its own and try to die and will eventually find its idle but when I go to get out on the road the car hesitates to accelerate so badly that it nearly stalls out I have to feather or pump the peddle to get it to go and get up to speed and as long as there are no major hills it drives fine if I don't have to slow down or stop then have to accelerate all over again
2003 Ford Mustang GT 4.6L with hard start and poor idle (only when warm) problem. Idle Air Control (IAC) valve was the problem and is a very common cause for idling and starting issues on these cars from 1999 through 2004.
i accelerate then let go of accelerater and sound like it has a tough time staying on