GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2008 🢒 TopKick C-Series (Conventional) C4/C5 🢒 Engine 🢒 Engine Controls and Fuel - 8.1L 🢒 Crankshaft Position Sensor Replacement
  1. Remove the air cleaner outlet duct.
  2. Remove the air inlet screen, if applicable.
  3. Inspect the throttle body bore and the throttle valve plate for deposits. You must open the throttle valve in order to inspect all of the surfaces.

    4. Notice: Do not subject a throttle body assembly which contains the following components to an immersion cleaner or a strong solvent:

       • Throttle position (TP) sensor
       • Idle air control (IAC) valve
       • Sealed throttle shaft bearings
    The cleaners will damage the electric components or sensors.

    The cleaners will damage some of these components that contain seals or O-rings.

    Solvents can wash away or break down the grease used on non-serviceable throttle shaft bearings.

    Never use a wire brush or scraper to clean the throttle body. A wire brush or sharp tools may damage the throttle body components.

    Do not use a cleaner that contains methyl ethyl ketone. This extremely strong solvent may damage components and is not necessary for this type of cleaning.

  4. Clean the throttle body bore and the throttle valve plate using a clean shop towel with GM Top Engine Cleaner, P/N 1052626 (Canadian P/N 993026) or an equivalent product.
  5. If the deposits are excessive, remove and disassemble the throttle body for cleaning. Refer to Throttle Body Assembly Replacement .

    6. After disassembly, clean the throttle body using a parts cleaning brush. DO NOT immerse the throttle body in any cleaning solvent.

  6. If you removed and disassembled the throttle body for cleaning, assemble and install the throttle body. Refer to Throttle Body Assembly Replacement .
  7. Install the air inlet screen, if applicable.
  8. Install the air cleaner outlet duct.