GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Geo 🢒 1997 🢒 Metro 🢒 Engine 🢒 Engine Controls - 1.3L 🢒 Throttle Body Assembly Overhaul

Disassembly Procedure
  1. Remove the throttle body fuel injection (TBI) unit from the engine. Refer to Throttle Body Assembly Replacement .

    2. Important: Do not to remove the fuel pressure regulator valve from the TBI unit. The fuel pressure regulator valve is calibrated at the factory and is not adjustable. The fuel pressure regulator valve is not serviceable separate from the TBI upper assembly.


    Object Number: 159161 Size: SH
  2. Remove the two bolts and the air cleaner bracket from the TBI unit.

    3. Object Number: 55777 Size: SH
  3. Remove the two screws (3) and the fuel injector cover (1) (with the electrical connector attached) from the fuel injector.
  4. Remove the two screws and the plate (2) covering the fuel injector wire leads.
  5. Remove the fuel injector wire leads from the TBI unit.

    6. Object Number: 55774 Size: SH
  6. Remove the fuel injector from the TBI unit.
  7. Remove the two screws and the throttle position (TP) sensor from the TBI unit.

    8. Object Number: 159165 Size: SH
  8. Remove the two screws to the upper and the lower sections of the TBI unit.
  9. Separate the upper (1) and the lower (2) sections of the TBI unit.

Assembly Procedure

    Object Number: 55780 Size: SH
  1. Install a new gasket (1) onto the TBI lower assembly (2).

    2. Object Number: 159165 Size: SH

    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.

  2. Install the upper TBI assembly (1) to the lower TBI assembly (2) and secure with the two screws.

    3. Tighten
    Tighten the TBI unit attaching screws to 3.5 N·m (31 lb in).

  3. Connect the TP sensor to the TBI unit.
  4. Secure the TP sensor to the TBI unit with the two screws, but do not tighten fully.

    5. Object Number: 165570 Size: SH
  5. Install a new lower fuel injector insulator into the fuel injector cavity of the TBI unit.

    6. Notice: Do not twist the fuel injector during the installation to the throttle body in order to prevent damage and misalignment of the fuel injector O-ring seals.

  6. Install the fuel injector to the TBI unit.

    7. Object Number: 55777 Size: SH
  7. Install the fuel injector wire leads into the TBI unit.
  8. Install the fuel injector wire lead cover plate (2) and secure with two screws.
  9. Install the fuel injector cover (1) (with the electrical connector attached) to the fuel injector and secure with the two screws (3).

    10. Object Number: 159161 Size: SH
  10. Install the air cleaner bracket to the TBI unit and secure with the two bolts.

    11. Tighten
    Tighten the ACL bracket bolt to 10 N·m (7.5 lb ft).

  11. Install the TBI unit onto the engine. Refer to Throttle Body Assembly Replacement .
  12. Adjust the TP sensor. Refer to Throttle Position Sensor Adjustment .