New TPS Fixed my Hanging Idle!

MLC Stang

Founding Member
Aug 23, 2002
Atlanta, GA

I’ve been chasing all the usual suspects trying to find the cause of the hanging idle my car started having a few months ago. I finally fixed it thanks to a hint from HISSIN50 that I found when I did a search and read a ton of posts on the subject.

I replaced my IAC valve first, since that is usually the culprit and mine was original with 108K miles on it. No good. I still had the hanging idle.

Next I did the throttle body “ring of gunk” clean up job, i.e. removing the ring of dirt that forms in your throttle body right where the butterfly valve seats in the bore. Over the years, a little ridge of dried on dirt forms there and blocks the flow of air past the butterfly valve when it is closed at idle. No good, still had the hanging idle.

One clue was that my hanging idle had the unusual quality of fixing itself if I turned off the engine and restarted it a few seconds later!!! Every time it happened, I could get it to stop for a while at least, if I just shut down and started back up. Even just in the time I was sitting and waiting for a light to change.

In a couple of posts in this topic HISSIN50 mentioned that a hanging idle that’s temporarily fixed by a restart is probably caused by a bad TPS (Throttle Position Sensor).

Well, even though the darn part was expensive, I got a new TPS and installed it. My hanging idle is GONE! Been driving for a week now and it’s stayed gone! Car even pulls away from a stop much smoother now as well. Must have been a bad spot on the pot in the TPS all along.

At any rate, thought I’d pass this info along as a possible fix for others who are chasing this problem, particularly if restarting your car temporarily fixes the idle.

And… I owe HISSIN50 a beer sometime!
  • Sponsors (?)


"How long does it take to get help in here?
15 Year Member
Nov 29, 1999
Hey, glad to hear you got it whipped. :nice:

I'm sure this thread will help a lot of fellow stangers in the future (that info about the hanging-idle-until-a-restart and TPS relationship is not something that gets posted too often). That particular issue often comes from contact debris inside the TPS (a wear and tear type of thing).

Your posts are always gems so it's nice that the forum was able to give a little something back. :nice: