Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

Adjusting Idle on TBI

Discussion in 'The Garage' started by blazer_87, Aug 18, 2004.

  1. blazer_87

    blazer_87 Registered Member

    Joined:
    Oct 1, 2001
    Posts:
    72
    Likes Received:
    0
    Location:
    Section, Alabama
    I have 87 TBI. It seems to be running rich and idling high. cant find an idle adjustment. Is there one? Any advice??? thanks in advance
     
  2. TrcksR4ME

    TrcksR4ME 1/2 ton status

    Joined:
    Feb 11, 2002
    Posts:
    2,482
    Likes Received:
    0
    Location:
    Seattle, WA 98103
    All I know is that the idle is computer controlled on TBI, you cannot manually adjust it. I think there is some sensor right in the throttle body that impacts how it idles.
     
  3. kd7kmp

    kd7kmp Registered Member

    Joined:
    Jun 2, 2004
    Posts:
    99
    Likes Received:
    0
    Location:
    Springivlle, Utah
    The idle on a TBI truck cannot be manually adjusted. Idle speed is controlled by the Idle Air Control (IAC) valve which is in turn controlled by the computer. Sometimes the passage used by the IAC gets gummed up. Clean the throttle body with carb cleaner. That should help.

    Kevin
     
  4. spearchucker

    spearchucker 1/2 ton status

    Joined:
    Nov 17, 2003
    Posts:
    1,556
    Likes Received:
    0
    Location:
    Bay area, CA
    Most of the time the throttle body gasket at the base is leaking. Spray some carb cleaner around the base and check if the idle increases slightly. If it does then just replace the gasket, simple fix.
     
  5. Emmettology 101

    Emmettology 101 3/4 ton status

    Joined:
    May 9, 2000
    Posts:
    8,126
    Likes Received:
    0
    Location:
    FL
    Not sure about on a stocker, but on my holley there is a throttle stop screw that allows you to adjust the idle. It on the front of the TB right in front of the trottle bracket..... According to their directions you are supposed to unhook the IAC and then set it.
     
  6. dyeager535

    dyeager535 1 ton status Premium Member

    Joined:
    Dec 13, 2000
    Posts:
    26,980
    Likes Received:
    189
    Location:
    Roy WA
    Instructions for setting idle are over on thirdgen.org in the tech section. IAC/TPS article IIRC
     
  7. blazer_87

    blazer_87 Registered Member

    Joined:
    Oct 1, 2001
    Posts:
    72
    Likes Received:
    0
    Location:
    Section, Alabama
    Thanks for the info on thirdgen.org. The passenger side of the TBI has two connectors, which one is the IAC? Thanks
     
  8. odee1

    odee1 Registered Member

    Joined:
    Feb 27, 2004
    Posts:
    50
    Likes Received:
    0
    the square on with four wires in it is the iac plug.
     
  9. Emmettology 101

    Emmettology 101 3/4 ton status

    Joined:
    May 9, 2000
    Posts:
    8,126
    Likes Received:
    0
    Location:
    FL
    The IAC is towards the back of the TBI on the pass side. The connector in the middle is the TPS.
     

Share This Page