Sticking Idle Rpms Raise When Clutch Is Pushed In?

Foxstang31

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Aug 11, 2015
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My 1990 mustang is idling like crap I have checked out jrinkers surging idle checklist but haven't gone through it yet because I couldn't find anything relating to my problem. I will go through it and actually check everything today. My problem is when my car idles at startup it idles around 1200 and comes down to 800 whenever it feels like it. But my rpms actually raise when i push the clutch in the come to a stop or shift?? It ranges from 2k-3,5k rpms when it does this. I pulled the codes I have koeo 15, 85 and koer 31 44 94. No catalic converters and the carbon canister was deleted. Any thoughts on what's going on?
 
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Clean out your IAC or test to make sure it's working. I just had this problem a few days ago and it ended up being a bad iac. It was getting stuck open while driving and the rpms would stick at around 2k when the clutch was pressed in. After that you could check your tps voltage.
Some people will probably post a better checklist soon but you can do those things until then.
 
Clean out your IAC or test to make sure it's working. I just had this problem a few days ago and it ended up being a bad iac. It was getting stuck open while driving and the rpms would stick at around 2k when the clutch was pressed in. After that you could check your tps voltage.
Some people will probably post a better checklist soon but you can do those things until then.
When I bought the car the guy gave me s new iac still in the box original ford. Looks new and I replaced it thinking it would solve my problem but no luck. Is there any way to check to see if the iac is working? I'll check my tps voltage when I get home also.
 
You guys with idle/stall problems could save a lot of time chasing your tails if you would go through the Surging Idle Checklist. Over 50 different people contributed information to it. The first two posts have all the fixes, and steps through the how to find and fix your idle problems without spending a lot of time and money. It includes how to dump the computer codes quickly and simply as one of the first steps. I continue to update it as more people post fixes or ask questions. You can post questions to that sticky and have your name and idle problem recognized. The guys with original problems and fixes get their posts added to the main fix. :D

It's free, I don't get anything for the use of it except knowing I helped a fellow Mustang enthusiast with his car. At last check, it had more than 200,000 hits, which indicates it does help fix idle problems quickly and inexpensively.
 
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You guys with idle/stall problems could save a lot of time chasing your tails if you would go through the Surging Idle Checklist. Over 50 different people contributed information to it. The first two posts have all the fixes, and steps through the how to find and fix your idle problems without spending a lot of time and money. It includes how to dump the computer codes quickly and simply as one of the first steps. I continue to update it as more people post fixes or ask questions. You can post questions to that sticky and have your name and idle problem recognized. The guys with original problems and fixes get their posts added to the main fix. :D

It's free, I don't get anything for the use of it except knowing I helped a fellow Mustang enthusiast with his car. At last check, it had more than 200,000 hits, which indicates it does help fix idle problems quickly and inexpensively.

I adjusted the tps to .97 and the idle doesn't raise anymore when I push the clutch in but it stays at 1900 rpms with clutch pressed in and on startup idles at 800?