GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Isuzu 🢒 2001 🢒 Isuzu T-Series (Truck Line C) 🢒 Engine 🢒 Engine Controls - 7.8L 🢒 Fuel Injector Replacement

Removal Procedure
  1. Tilt the cab. Refer to Cab Tilting in General Information.

    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.

  2. Disconnect the negative battery cable.

    3. Object Number: 736592 Size: SH
  3. Disconnect the two-way valve (TWV) harness connectors at the outside of the lower case, under the valve rocker arm cover.
  4. Remove the injection pipes between the injector (4) and the supply pump.
  5. Remove the valve rocker arm cover. Refer to Valve Rocker Arm Cover Replacement in Engine Mechanical.
  6. Disconnect TWV harness connector from inside of the lower case joint connector.
  7. Loosen the terminal nuts for TWV harness on the top of the injector and remove the TWV harness.
  8. Remove the TWV harness assembly from the top of the rocker arm assembly.
  9. Loosen the injector clamp bolt (1) then remove the injector assembly.

Installation Procedure

    Object Number: 736683 Size: SH
  1. Install the injector clamp on the valve spring seat.

    2. Object Number: 736592 Size: SH
  2. Assemble the fuel injector (4) and injector clamp (7) as a complete assembly first, then temporarily install the injector assembly together with the clamp into the injector sleeve hole.
  3. Temporarily tighten the injection pipe to the injector.

    4. 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. Apply molybdenum disulfide grease to the clamp bolt.

    5. Tighten
    Tighten the injector clamp bolt to 31 N·m (22 lb ft).

  5. Tighten the injection pipe.

    6. Tighten
    Tighten the injection pipe to 44 N·m (33 lb ft).

    Important: Ensure that the injection pipe and return pipe eye bolt are tightened. This will prevent the dilution of the engine oil. Ensure that the gasket for the return pipe does not ride on the injector body when tightening the eye bolt.

  6. Install the fuel return pipe on the two-way valve (1).

    7. Tighten
    Tighten the fuel return pipe eye bolt to 41 N·m (31 lb ft).


    Object Number: 736685 Size: SH
  7. Install the two-way valve (TWV) harness assembly.

    8. Tighten
    Tighten the fixing bolt to 22 N·m (16 lb ft).

  8. Install the TWV harness to TWV terminals (1). Tighten the fixing nut by hand until the nut reaches the harness terminals.

    9. Tighten
    Tighten the fixing nut to 2 N·m (17.7 lb in).

  9. Reconnect the TWV harness to lower case joint connector.
  10. Install the valve rocker arm cover. Refer to Valve Rocker Arm Cover Replacement in Engine Mechanical.
  11. Reconnect the two TWV harness connectors at the outside of the lower case.
  12. Connect the negative battery cables.
  13. Lower the cab.