I have an 88 mustang gt, 5.0L HO, fuel injected...

All of a sudden one day on my way home when i came to a red light, my car idled at like 2,000 rpms. It only does this once i have been driving for awhile and the enigines warm, especially after highway driving. it will idle between 1,800 and 2,000 when in nuetral or with the clutch engaged. if i let it idle like that it will eventually idle down after about 2 full minutes (a long red light) If i shut the car off and start it back up maybe an hour later (but the engine still warm) it wont do it right away. This is very aggravating, annoying and embarassing. Is this a sensor? TPS, or MAP? Has anyone had and solved this same problem? Any and all help is greatly appreciated...

Thank you

 

Clean the IAC?

 

it sounds like you have a vacuum leak somewhere on the engine, i would check all of your hoses and see if thats it.

 

Well i tried cleaning the iac and it idled higher when cold. even with the carb cleaner well burned out of the system. i then unplugged the electrical connector from the iac and it idles better hot, cold, and after a long drive. i dont see why not just leave it unplugged...

 

i bought my car and the iac was unplugged it wouldnt start unless u had the gas on the floor and it wouldnt idle cold the iac motor was bad and i also had a problem with a tb i bought from a friend and i didnt realize the butterfly was cracked id go with finding out if u have excessive air ie a vacuum leak and/or replacing your iac it worked for me

 

never leave a sensor or anything unplugged it will just ruin your car and you do not want that either replace the part or find what is really wrong. but replace that iac it is inexpencive, if that doesnt work check for a vacuum leak.

 

exactly