!PROBLEM! Mustang won't idle

Discussion in 'SN95 4.6L Mustang Tech' started by Bigbofus, Jan 10, 2007.


  1. Bigbofus

    Bigbofus New Member

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    Hey everyone. I am having a problem with my '96 GT. Basically, when I start it up the engine revs but then the RPMs immediately drop and the car dies. I can keep it going by keeping my foot on the gas but as soon as I let off the RPMs once again drop and the car dies. I drove it like this for about 20 mins and halfway through the drive it started to idle although at about 500 RPMs, it wasn't dying though. Do any of you know what could be wrong? This happened before and I thought I fixed it by changing the fuel filter. After I did that it worked for another few months before this started happening again. Thanks!

    Zach
    #1
  2. d98gt

    d98gt Founding Member

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    [​IMG] Give your IAC a good cleaning since it's failing on you.

    If cleaning it doesn't help, then you'll need a new one :nice:
    #2
  3. MaxxMundo

    MaxxMundo Member

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    Also, if it doesn't want to start, you can give the IAC a tap with the handle of a screwdriver. That will usually loosen it up and allow you to drive without any problems until the engine cools down. Just a temporary solution until you purchase a new one.
    #3
  4. blacksheep-1

    blacksheep-1 Member

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    Yes the Idle motor is the most likely problem, clean it out and reinstall it. While you're at it hose out the throttle body as well. There could be another issue, but it's probably unlikely in your case. The A/c switch located on the pass side rear of the engine compartment could also be acting up. This could be from a low freon level. The symptoms are similar, which is erractic idel, if the freon is OK then (if it's as tock switch) there is an allen screw inside it once you pull the electrical plug off, try screwing it in (or maybe out, it's been awhile) and this will adjust the sensitivity of the switch. Or you could just replace the idle motor and/or the a/c switch. Anyway, start with the idle motor.
    #4
  5. fast97gt

    fast97gt Active Member

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    dude its deff. the iac (idle air control motor or valve) what happens most of the time oil,carbon and dirt most of the time build up on the pintle inside and stops it from sliding the valve back and forthto let the required air to keep the engine at idle. other times but rarely the electronics go bad inside of it so dont waist your time cleanig that peice spend your money and buy a new one, spend a little more and get a quality peice from ford, cause theres 50/50 chance afer cleanig that itll work for awhile if not at all, and yea use a good intake cleaner to clean the throttle body
    #5
  6. DTNODYA

    DTNODYA Member

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    I agree with everyone ....

    On my B4000 (Ranger), it started acting crazy like how you described your car is running and it turned out to be my crankshaft position sensor. But it threw a CEL and that's how I knew it was that sensor. So if you aren't getting a check engine light, it's either your IAC, MAF, TB, etc., but most likely your IAC.
    #6
  7. scupking

    scupking Active Member

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    I'm haveing the exact same problem with my 01GT. I cleaned my IAC and I still have the problem but it only happens when its damp out.
    #7
  8. JimC

    JimC Member

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    +1 Deff the IAC. I had the same issue on my 01 gt
    #8
  9. BlackGT4.6

    BlackGT4.6 New Member

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    I had the same problem with mine. Iac are cheap i would just replace it. cleaning might work but it might not you know a new one will.
    #9
  10. DTNODYA

    DTNODYA Member

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    Are you all (those who have replaced their IAC), buying them from Ford or aftermarket and how has your luck been?

    When you say cheap, how much are they? For my truck they are pricey ...
    #10
  11. streethorse

    streethorse Active Member

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    The Ford IAC cost me about $90. Ford really owes most of us a free one.:mad:
    #11
  12. d98gt

    d98gt Founding Member

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    I guess I am one of the lucky ones :shrug:. I cleaned it way over a year ago and have never had a problem since :)
    #12
  13. 313blkstang

    313blkstang New Member

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    I have a '96 GT as well and I experience this same exact problem.. Mine only happens very sporadically (maybe once or twice a month). And just like you in order to drive it I have to put it in neutral and give it gas in order for it not to shut down.. Usually after about 15-20 minutes it "fixes" itself and drives normallly. Or when it does this I'll just leave it off and come back in like 20 minutes and it starts right up like nothing ever happened.. I just replaced my IAC about 1.5 years ago, could it be bad again already?
    #13
  14. DTNODYA

    DTNODYA Member

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    Amen to that. :flag:

    They could throw in a throwout bearing also ....:nonono:
    #14
  15. 2013 Geee T

    2013 Geee T Founding Member

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    Will that fix a surging idle too?
    #15

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