GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1998 🢒 Chevrolet C-Series Medium Duty Truck B7 🢒 Engine 🢒 Engine Controls - 6.0L and 7.0L 🢒 Throttle Body Assembly Replacement

Removal Procedure

    Caution: Unless directed otherwise, the ignition and start switch must be in the OFF or LOCK position, and all electrical loads must be OFF before servicing any electrical component. Disconnect the negative battery cable to prevent an electrical spark should a tool or equipment come in contact with an exposed electrical terminal. Failure to follow these precautions may result in personal injury and/or damage to the vehicle or its components.

  1. Remove the negative battery terminal.
  2. Loosen the filler cap in order to relieve the fuel system pressure.
  3. Remove the air cleaner assembly, the extension, and the gasket. Refer to Air Cleaner and Extension Replacement .
  4. Remove the TBI unit from the engine. Refer to Throttle Body Injection (TBI) Unit Replacement .
  5. Remove the fuel inlet nut and O-rings, the fuel outlet fitting, and the gasket from the fuel meter body assembly.

    6. Discard the O-rings and the gasket.

  6. Remove the fuel meter body to throttle body attaching screws.
  7. Remove the fuel meter body assembly and the gasket from the throttle body.

    8. Discard the gasket.

  8. Inspect the replacement throttle body for items that you will need from the unit removed from the engine.
  9. Disassemble the TBI unit following the component replacement procedures. Refer to Throttle Body Injection (TBI) Unit Replacement .

Installation Procedure
  1. Assemble the replacement throttle body with transferred parts following the component replacement procedures. Refer to Throttle Body Injection (TBI) Unit Replacement .
  2. Install the new throttle body to the fuel meter body gasket.
  3. Install the fuel meter body assembly on the replacement throttle body.
  4. Install the fuel meter body to throttle body attaching screws coated with appropriate thread-locking compound.

    5. Tighten
    Tighten the fuel meter body attaching screws to 4.5 N·m (40 lb in).

    Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

  5. Lubricate the fuel inlet nut O-rings with engine oil.
  6. Install the fuel inlet nut with two new O-rings and the fuel outlet fitting with the new gasket to the fuel meter body assembly.
  7. Install the TBI unit with the new TBI gasket onto engine.

    8. Tighten

        • Tighten the fuel inlet nut fitting 41.0 N·m (30 lb ft).
        • Tighten the fuel outlet fitting to 41.0 N·m (30 lb ft).
  8. Install the new fuel O-rings on the fuel feed and return lines.
  9. Install the fuel lines.

    10. Tighten
    Tighten the fuel line nuts to 27 N·m (20 lb ft) using a backup wrench on the TBI fuel fittings in order to prevent them from turning.

  10. Connect the negative battery terminal.
  11. With engine OFF and ignition ON, check for fuel leaks.
  12. Install the gasket and the extension.
  13. Position the air cleaner assembly on the TBI unit in order to allow access to the idle stop screw. Refer to Air Cleaner and Extension Replacement .
  14. Adjust the minimum idle speed. Refer to Minimum Idle Speed Check .