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how to change throttle body gasket

Discussion in 'Chevy Suburban Forum (GMC Yukon XL)' started by 89suburban350, Jul 16, 2007.

  1. 89suburban350

    89suburban350 Rockstar 100 Posts

    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. 84fiero123

    84fiero123 Epic Member 5+ Years 1000 Posts Platinum Contributor

    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.
  3. Cableguy

    Cableguy Epic Member 5+ Years ROTM Winner 1000 Posts

    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.
  4. Crawdaddy

    Crawdaddy Thread Killer Extraordinaire Staff Member 5+ Years 1000 Posts Platinum Contributor

    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
  5. Cableguy

    Cableguy Epic Member 5+ Years ROTM Winner 1000 Posts

    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....:no: Who needs eyebrows...:sarcastic:
  6. 84fiero123

    84fiero123 Epic Member 5+ Years 1000 Posts Platinum Contributor

    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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