1. Can’t make it to the GIE+EXPO 2017?
    LawnSite brings the trade show floor to your fingertips with our new GIE+EXPO 2017 Sneak Peek video series debuting now in the Lawn Mowing forum.

    Dismiss Notice

99 Silverado idle too high

Discussion in 'Trucks and Trailers' started by KeystoneLawn&Landscaping, Mar 11, 2009.

  1. KeystoneLawn&Landscaping

    KeystoneLawn&Landscaping LawnSite Senior Member
    Messages: 774

    I recently cleaned the throttle body and after I did I got a check engine code.Two things...too high idle, which is obvious....and running too lean. Ideas how to adjust without going to my mechanic? Thanks
  2. Ironic

    Ironic LawnSite Senior Member
    Messages: 353

    I think you can just keep running it, and it will clear itself. I have a 96 S-10 that did the same thing after I cleaned the throttle body, and used Sea Foam. it really had me worried for a bit cuz it would not come down below 1500 rpms...but I went and drove it for a few miles, and when I got back it was fine. good luck, I hope it works for ya!
  3. topsites

    topsites LawnSite Fanatic
    Messages: 21,653

    You could try the simple trick, which up under the hood at the throttle body...
    Where the throttle cable hooks up, there's that whole throttle control thing...
    There should be an idle speed limiter screw to adjust the idle speed, I'd see if
    turning that down some slows it.

    And it might not, but that would be the first thing I would try is to adjust it with a screwdriver.
  4. 4.3mudder

    4.3mudder LawnSite Silver Member
    Messages: 2,227

    I don't think those throttle bodies have crub idle screws, it is all done by the computer.
  5. KeystoneLawn&Landscaping

    KeystoneLawn&Landscaping LawnSite Senior Member
    Messages: 774

    My truck did have the idle adjustment screw, and didn't take much of a move to get where it needed to be. Thanks to all for the input!

Share This Page