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  1. #1
    Jr. Mechanic
    Join Date
    Aug 2006
    Location
    Wesley Chapel, Fl
    Posts
    140

    Default how to change throttle body gasket

    can anyone guide me through this? i am having such a hard time i never mess with the fuel system so i thought i'd ask someone on here...

  2. #2

    Default

    Before changing anything I would test it. I know this has to do with your high idle so here is an old school test, I love old school, low tech testing, ask anyone on here.

    With the engine running and the air cleaner off get a spray bottle, like an old Windex bottle. Fill it will plain water. Now spray around the bottom of the throttle body, where the gasket is. (you can also use starting fluid, but don’t).

    Now pay attention to the idle speed, if there is a leak at the gasket the idle will change, rise or lower depending on the problem.

    No change, no problem. If the idle changes then there is a problem. Get a gasket and change it. Just remember that a vacuum leak around the intake or a vacuum line can also cause an idle problem.

    I have had vacuum leaks in fuel injection systems cause all sorts of problems, from idle surges to no start.

    Once you are sure that you have vacuum leak, and where it is we will go about fixing it.

    I just don’t like throwing parts at a problem, test, test, test.

    Technology is great, when it Works,
    And one Big Pain in the Ass When it Doesn’t.
    Detroit Iron Rules, All the Rest are Just Toys.
    94 GMC Burban, 5.7L (350), 4X4, Auto
    86 GMC Burban, 350, 2 WD, Auto
    79 GMC pickup plow truck, 400, Full time 4X4, Auto
    86 Pontiac Fiero SE, 2.8L, Auto, only mid engine American car
    See a Pattern yet?

    15 year GM assembly line worker.

  3. #3

    Default

    I did this on my 89 305 1/2ton...but do you think I can remember. I think I remember undoing bolts out thru top gently work old gasket out (If it cracks careful not to drop gasket bits down into intake) and slipping gasket in underneath it cuz intake side looked clean (I didn't need to scrap gasket) I used to test for leaks using a propane cylinder turned on but not lit. Then I moved it around area in question tell idle came up. I could be leaking from some of the other hose too.



    Jamie

    2007 Ford E250(Work van) (Ya, Ya, shut up!)
    1996 GMC Sierra SLE 1500 5.7L/4L60E

  4. #4

    Default

    Quote Originally Posted by Cableguy View Post
    I used to test for leaks using a propane cylinder turned on but not lit. Then I moved it around area in question tell idle came up.
    Thank God you're still alive Jaime....That don't sound too safe or smart That's like looking for a gas or propane leak with a lit match lol
    Christopher

    1991 Chevy Suburban 1/2 ton 2WD w/ chevy SBC 350-3/4 ton drivetrain upgrade w/4.10 gears 200K miles
    2005 Saturn ION-2 Stock 265K miles
    1982 Bronco, 1993 Bronco (sold), 1971 M35A2 Deuce and a Half



    There are 10 kinds of people, those who understand binary, and those who dont...

    Remember kids, the only difference between screwing around and science is writing it down- Adam Savage

  5. #5

    Default

    He He He What like using ether to mount a truck tire....Now thats cool to watch!

    I used a little propane bottle with the extension hose on it....What eyebrows.... Who needs eyebrows...:sarcastic:

  6. #6

    Default

    Quote Originally Posted by Crawdaddy View Post
    Thank God you're still alive Jaime....That don't sound too safe or smart That's like looking for a gas or propane leak with a lit match lol
    LOL

    But it works.

    You may not be around to fix the leak after you find it.

    Thats why i didn't recomend the starting fluid test.

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