the OFFICIAL "crazy idle" thread

Discussion in 'Fox 5.0 Mustang' started by D347643, Jan 12, 2004.

  1. D347643 Banned

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    ok, i (like many other stang owners) have idle problems. I see tons and tons of threads with people asking for help with their idles and i want to make this the thread to end all (for a while at least.) Anyone who knows about idle problems with fuel injection please tell us your symptom and how you solved it OR if someone has a paper already written dealing with fixing mustang idle probs then please post that as well, and how you go about fixing it (checking tps voltage, etc)

    thank you for any info

    Drew :flag:
  2. 1BAD89GT New Member

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    "Crazy Idle" Intake Swap

    Car:89 Mustang GT
    Upgraded stock Intake to a new Cobra Intake,I installed the cobra Intake made sure to hook all the sensors and what vacum lines i had back up to new intake for the most part they hooked up alike...but when i tried to start the car it would not idle at all and would only stay running if i kept my foot slightly on the gas pedal,And it sounded like it was missing on every cylinder.Finally had one of my buddies jump in and start it and keep it running while i checked the Intake,got to listening real close to the intake and i could hear what almost sounded like a vacuum leak on the Bottom of the intake,got to feeling around and found a large vacuum leak on bottom backside of intake where i had forgotten to cap off a nipple for a vacuum line.slapped a vacuum cap on it and when we restarted the car it purred like a kitten.
  3. colemanitis New Member

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    My car idles like it has a mild cam in it for maybe a minute after startup. My mechanic found a small exhaust leak due to an old, worn out throttle body gasket. Since the old TB has to come off to replace the gasket, I'm trying to decide If I want to go ahead and slap a larger (65mm) TB on.
  4. willys1 Banned

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    Ever since I put my cai on when I have the heat,or defrost on,it bounces (the idle) up and down about 200 rpm's.Its been to ****in cold to look for vacum leaks!!
  5. Mavrick Founding Member

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    I remember reading a HUGE thread about wondering/surging idles, either on here or on the Corral.

    The idea was to clean your 10-pin connectors, and seperate the ends to make better connections.
  6. willys1 Banned

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    Really? Where is that?
  7. D347643 Banned

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    bump, haha i know people are having idle probs!
  8. noslow5_0 New Member

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    well i have had way to many probs trying to get my car to idle right.. Replaced IAC valve, purchased some idle air adjuster, cleaned the throttle body intake with carb cleaner, checked for any vacum leaks an nothing. Turns out the guy i bought the car from didnt know that an adjustable fuel pressure regulator meant that you had to adjust it!!! Car was runnin at 18psi with vacum off... Cranked up the pressure to 40 then it idled great for a day or two. When my lights an heater are off its doesnt idle that great, but when i put turn them on its fine. Dont know what that has to be... But now that i have rambled on... bump for you!!!!
  9. 65ShelbyClone Founding Member

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    The big round black and white plugs behind your fuel pressure regulator.
  10. TheUser Active Member

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    next time use throttle body cleaner :nice: I've read something about carb cleaner messes the throttle body's up
  11. Black331Stang New Member

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    you are too late there is already an official surge demon thread lol...thats y not many responses. Cause like u said, you've seen 100's of these post, y not use them? theres one wit like 50 pages i think.

    Anyway, ive heard of the 10 pin connector thing, they are right behind the upper intake, also known as "salt and pepper shakers"
  12. 67coupe Founding Member

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    I've been through this and I think I have it beat. Here's what it took for my car.

    New IAB - probably wasn't neccessary
    New TPS - (same as above)
    Cleaned and spread 10 pins - also eliminated extension
    New ECT
    New ACT - car idle better, bad sensor caused rich, rough idle
    Even plugged the vac line going to the EGR Valve - no help

    Still had problems after all of this. Then I carefully reset the idle per the instruction on the corral (www.corral.net). Fixed my problem.

    Some of these computers are very stubborn. They want to idle at the factory setting. (~650-700rpms) Apparently the relationship between the throttle body adjustment and TPS adjustment is very touchy. I had bumped my idle up in the past. I think I had my throttle body blade open a little to far. I actually set the idle lower using the adjustment screw, then set the TPS to 0.97 volts. Since then, it has purred like a kitten at idle.

    I didn't do a good job of explaining this, but don't under-estimate the importance of going through the whole process and setting the idle correctly.

    Good Luck
  13. Hourang New Member

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    i used brake cleaner :nice:
  14. Hourang New Member

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    :lol: exhaust leak :rlaugh:

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