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  1. #1

    Default Extremely High Idle please help

    Hello, before I get flamed I did try the search function first. Ok. I have a 1987 S10 with a 2.5 4cyl and a manual trans. When I start it, it immediately starts to idle higher than heck. It will not idle down at all. The previous owners put in a new trottle position sensor. No change. Also no check engine lights. Does the Idle Air Controller affect idle that much? I don't know what else to try. Any help or tips would be greatly appreciated. Thank you.

  2. #2


    it certainly does. definitely worth checking into, although I'm not exactly an expert on the subject.
    1994 Chevrolet C1500 Pickup
    Regular Cab, Long Bed, 2 wheel drive.
    4.3L Vortec V6 '262 CID'
    333,000 miles and counting....with a gallon of gas every 14.

  3. #3


    Make sure the connections on the TPS are tight. I seem to remember there's a connector that has to be unplugged to set the timing. If this connector is left plugged in it causes a high idle. Not sure if this applies to your truck. Do a search here for repair manual and there's a link to the Ohio library where you can access the Mitchell repair information for your truck.

    2004 SILVERADO 2500HD LS
    Pro Comp Leveling Kit
    285-75-16 Cooper ST All Terrains
    Pro Comp Programmer
    Bilstein Shocks
    Linux Bed Liner
    Tinted Windows

    Other rides:

    1967 Landcruiser <350 Chevy>
    1970 Camaro
    1990 Geo Metro Convertible
    2007 FJ Cruiser

  4. #4
    Legend cascott325's Avatar
    Join Date
    Aug 2008
    Lawrenceburg, Kentucky


    check all your vaccume lines for breaks and dry rotting, do a tune up, plugs wires, cap and botton, etc. seafoam intake, break booster, gas tank.
    2000 silverado with a 5.3l v8, shorty headers, upgraded plugs, 10 mil wires, magnaflow high flow cats, flowmaster 80 series muffler(2 in 2 out) w/ 18 inch stainless silverline tips. i have a k&n CIA. its a 4x4 z71 offroad package. Ls model.
    extended cab 160k miles, truxedo low profile bed cover, diablo sport predator tuner.
    reman tranny @ 130k miles

  5. #5


    Thanks everyone, I will give the seafoam a shot tonight and check all vaccum lines. I will post my progress. Thanks again.

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