High Idle After Stopping

Discussion in '1996 - 2004 SN95 Mustang -General/Talk-' started by macorden, Jul 21, 2014.

  1. Hi all. I've recently purchased a 96 cobra after owning a 95 and wonder if this is normal and if not what should I look for to repair. After driving and coming to a stop the car idles at 1800 rpm for 5-10 seconds and drops down to 800. It also idles like this after the initial starting of the motor. Is it normal for these 4.6 to idle high like this? Thanks!
  2. I have a 2002 V6. I know yours is different than mine, But this part helped with the surge when stopping or stopped and idle at start up http://www.amazon.com/gp/product/B0018RBQ16/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1 Exhaust Gas Recirculation pressure feedback sensor. When I finally changed this I think I was totally satisfied. and I had also bought a idle control sensor. Cleaning mine didn't help. Plus checking for vacuum leaks too helped a little.

    Usually people are going to tell you this : Idle Air control, Throttle body sensor (You may have an adjustable one) and to clean the IAC (Idle air control). When I first bought mine last year I did a process of elimination. LOL Change all the hoses, Most sensors, Fuel filter,etc. Check for coupon codes for some Auto parts stores. That how I saved a ton. I wish you the best.
    #2 Suek, Jul 21, 2014
    Last edited: Jul 21, 2014
  3. I have had this issue before on a couple of my stangs. What usually fixes it is a new TPS (throttle positioning sensor). But just word for the wise, I have bought new TPS's and it still did the high idle, but I would buy them from places like AutoZone, but then I went to Ford and replaced it with a OEM and it worked fine. But keep in mind that just cause a part is new does not mean it is a good part. Sometimes you have to return the new part for another. But the price from Ford and the auto parts store was practically the same. But by first hand experience with this problem a few times, a TPS is in your future. And they are cheap to replace and takes all of 5 minutes to do the job. I by nature always disconnect the battery whenever I am replacing an electrical part. Would suggest the same to you. Hope this helps.
  4. Take a look at your IAC (Idle Air Controller), these Mustangs are notorious for having problems with them. A lot of people have gotten away with just cleaning it while others have not. Always try to replace it with a genuine Ford part, don't scrimp here to save a few bucks.
  5. +1 on the IAC, I would check for a vac leak too...

    You can check the TPS with a DVOM

    I recommend this website for ANYONE that needs a little help. This guy explains how to diagnose and test by process of elimination so that your not throwing parts at the car and wasting your hard earned $$$.

    Suek likes this.
  6. Weird idle issues is how you know you are driving a Mustang! :)
  7. Thank you. I seen on this website how to test a relay. That's what I needed!