GM Service Manual Online
For 1990-2009 cars only

Removal Procedure

  1. Relieve the fuel pressure. Refer to Relieving Fuel Pressure in Engine Controls.
  2. 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.

  3. Disconnect the negative battery cable.
  4. Drain the engine coolant. Refer to Cooling System Draining and Filling in Engine Cooling.
  5. Remove the air cleaner assembly.
  6. Disconnect the following electrical connectors:
  7. • The engine coolant temperature (ECT) sensor connector
    • The coolant temperature sending unit connector
    • The throttle position (TP) sensor electrical connector
    • The exhaust gas recirculation solenoid vacuum valve
    • The idle speed control (ISC) motor electrical connector
    • The ground wire bolts and the ground wires from the intake manifold
    • The throttle body fuel injection (TBI) unit electrical connector
    • The early fuel evaporation (EFE) heater electrical connector, if necessary
    • The release wiring harness from the retaining clamps

    Object Number: 177818  Size: SH
  8. Remove the fuel return hose (2) and the fuel feed hose (3) from the TBI unit (4).

  9. Object Number: 177815  Size: SH
  10. Remove the coolant hoses (2, 3, and 4) from the TBI unit and from the intake manifold.
  11. Remove the EGR modulator.
  12. Remove the EGR valve.
  13. Remove the following vacuum hoses:
  14. • The evaporative emissions (EVAP) canister hose from the EVAP canister pipe
    • The manifold absolute pressure sensor hose from the throttle body (TB)
    • The brake booster hose from the intake manifold
  15. Remove the positive crankcase ventilation (PCV) hose from the cylinder head cover.
  16. Remove the accelerator cable from the TBI unit.

  17. Object Number: 177810  Size: MH
  18. Remove the five nuts and the two bolts from the intake manifold.
  19. Remove the intake manifold (4).Remove the TBI unit (1) and the wire clamps from the cylinder head with the intake manifold.
  20. Remove the intake manifold gasket (5) from the cylinder head.

Installation Procedure


    Object Number: 177810  Size: MH
  1. Install the new intake manifold gasket (5) to the cylinder head.
  2. Install the intake manifold.Install the TBI unit (1) and the wire clamps to the cylinder head with the intake manifold.
  3. 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.

  4. Secure the intake manifold with the five nuts and with the two bolts.
  5. Tighten
    Tighten the intake manifold fasteners to 23 N·m (17 lb ft).

  6. Install the PCV hose to the cylinder head cover.
  7. Install the following vacuum hoses:
  8. • The EVAP canister hose
    • The manifold absolute pressure sensor hose to the intake manifold or to the TB
    • The brake booster hose to the intake manifold

    Object Number: 177815  Size: SH
  9. Install the coolant hoses (2, 3, and 4) to the TBI unit (4) and to the intake manifold.

  10. Object Number: 177818  Size: SH
  11. Install the fuel return (2) and the fuel feed (3) hoses to the TBI unit (4).
  12. Connect the following electrical connectors:
  13. • The ECT sensor electrical connector
    • The coolant temperature sending unit connector
    • The EFE heater electrical connector, if necessary
    • The ECT switch electrical connector
    • The TP sensor electrical connector
    • The EGR solenoid vacuum valve electrical connector
    • The ISC motor electrical connector
    • The ground wires to the intake manifold
    • The TBI unit electrical connector
  14. Secure the wiring harness to the retaining clamps.
  15. Install the accelerator cable to the TBI unit.
  16. Adjust the accelerator cable play to specifications. Refer to Accelerator Cable Replacement in Engine Controls.
  17. Install the air cleaner assembly to the TBI unit.
  18. Reconnect the negative battery cable.
  19. Refill the engine coolant. Refer to Cooling System Draining and Filling in Engine Cooling.
  20. Upon completion of the installation, start the engine, and inspect the intake manifold for fuel leaks and for engine coolant leaks.