5.0L (1979-1995) MustangTechnical discussions on 5.0 Liter Mustangs within. This does not include the 5.0 from the 2011 Mustang GT. That information is in the 2005-1011 section.
Sponsored by Weld Racing
Welcome to Mustang Forums!
Welcome to Mustang Forums.
You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, at no cost, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!
I have a 95 gt that started out while driving at highway speeds and come to a stop it would sometimes stay at 2000 rpm. If i turned the car off and back on it would idle normal again and everything was fine. I was told by a friend that it was either the IAC or the TPS so i changed both of them and now the was will not idle below 1300 rpm at all and when you drive it and go to shift gears as you push the clutch in it will idle up to almost 4000 rpm. If you are sitting and car idling at 1300 and rev the engine it is very very slow to come back to the high idle of 1300. When I changed the IAC and TPS I disconnected the battery for a while and for some stupid reason didn't check my codes before because the guy that told me what the issue was is usually pretty knowledgable with these cars but no such luck this time.
Since i change the IAC and TPS and the car when from just a periodic high idle that could be fixed with a restart of the car to a constant high idle even when idling i put the old IAC and TPS back on and still have the same high idle issue.
Please any help would be great I need to get this car back on the road.
This ad is not displayed to registered or logged-in members. Register your free account today and become a member on Mustang Forums!
Also something else to take in account. If i remove the air intake off the throttle body still with all sensors hooked up it will idle down to around1000 but not all the way to the normal 750-800 range. Then i hook the intake back to the throttle body and it idles right back up to 1300. It is still slow to idle back down if revved up with air intake hose off though.
I'd have to say you should go right to the TPS and base idle reset with this one. If that's not it, go to a junkyard for an OEM IAC to rule it out as the source. Look for one that looks decent, inside an out, to minimize the chance that you end up with a bad one. Clean it out with some carb cleaner and Q tips before you install it.
'89 GT, 5-speed, (because it's boring when the car does it FOR you), freshly rebuilt engine and tranny, GT-40 heads, Performer upper and lower intake, 130 amp alternator, K&N, alternator upgrade with Taurus fan, DCC fan control, subframes, Cobra R 17X9's.
I could only get it down to .99 and it was still idling at 1000 rpm. So I'm taking it off and going to try to drill the holes out just a bit and try to get it closer to .9 that seems like it might do the trick or at least i hope so.
I got the voltage of the fps to .9 and the idle is still right at 1000 rpm. I checked the voltage on the IAC while running. The white wire w/ blue stripe has 13.4 volts and the red wire has 14.4 volts. Is that normal?
iv gotten it down to idle about 800-900 but it is still wanting to hang at 1300 for a few seconds before dropping down to the 800-900. also it won't drop down to the low idle speed until the car is fully stopped and in neutral with clutch released.
My 94 was like that too for a while. You just have to drive it for a while and let the adaptive learning of the ecm do its thing. I suspect it will likely get better with the more miles you put on it. The computer is programmed to keep a higher idle between shifts , once it learns how you drive it will likely level it self out.
This forum is owned and operated by Internet Brands, Inc., a Delaware
corporation. It is not authorized or endorsed by the Ford Motor Company and is not affiliated with the Ford
Motor Company or its related companies in any way. Ford® is a registered trademark of the Ford Motor