GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Isuzu 🢒 2005 🢒 Isuzu MD F-Series 🢒 Engine 🢒 Engine Controls - 7.8L 🢒 Fuel Injector Replacement

Removal Procedure
  1. Tilt the cab. Refer to Cab Tilting .
  2. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection .
  3. Disconnect the 2-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 and the supply pump.
  5. If required, remove the exhaust gas recirculation (EGR) cooler pipe. Refer to Exhaust Gas Recirculation Pipe Replacement .
  6. Remove the valve rocker arm cover. Refer to Valve Rocker Arm Cover Replacement .
  7. Disconnect the TWV harness connector from inside the lower case joint connector.

    8. Object Number: 1401144 Size: SH
  8. Loosen the terminal nuts (1) for the TWV harness on the top of the injector and remove the TWV harness.
  9. Remove the TWV harness assembly bracket from the top of the rocker arm assembly.

    10. Object Number: 736592 Size: SH
  10. Remove the return pipe eye bolt (2) and the return pipe (3) from the injector (4).

    11. Notice: Do not forcefully pull the injector pipe free. Doing so will loosen the nozzle sleeve and water leakage may result in damage to the engine.

  11. Remove the injector clamp bolt (1) and clamp (8) from the cylinder head.
  12. Remove the injector assembly (4).

Installation Procedure

    Object Number: 736683 Size: SH
  1. Install the injector clamp (8) on the valve spring seat.

    2. Object Number: 736592 Size: SH
  2. Assemble the fuel injector (4) and injector clamp (8) as a complete assembly.
  3. Temporarily install the injector assembly (4) together with the clamp (8) into the injector sleeve hole (6).
  4. Temporarily tighten the injection pipe (5) to the injector (4).

    5. Notice: Refer to Fastener Notice in the Preface section.

  5. Apply molybdenum disulfide grease to the clamp bolt (1).

    6. Tighten
    Tighten the injector clamp bolt (1) to 31 N·m (22 lb ft).

  6. Tighten the injection pipe (5).

    7. Tighten
    Tighten the injector pipe bolt to 44 N·m (33 lb ft).

    Important: 

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

  7. Install the fuel return pipe (3) on the injector (4) with the return pipe eye bolt (2).

    8. Tighten
    Tighten the fuel return pipe eye bolt (2) to 14 N·m (10 lb ft).

  8. Install the TWV harness assembly bracket.

    9. Tighten
    Tighten the TWV harness bracket bolts to 22 N·m (17 lb ft).


    Object Number: 1401144 Size: SH
  9. Install the TWV harness to the TWV terminals (1). Tighten the nut by hand until the nut reaches the harness terminals.

    10. Tighten
    Tighten the TWV terminal nut to 2 N·m (18 lb in).

  10. Reconnect the TWV harness to the lower case joint connector.

    11. Object Number: 1402402 Size: SH
  11. Inspect and record the ID code from the injector.
  12. Install the valve rocker arm cover. Refer to Valve Rocker Arm Cover Replacement .
  13. Reconnect the 2 TWV harness connectors at the outside of the lower case.
  14. If required, install the EGR cooler pipe. Refer to Exhaust Gas Recirculation Pipe Replacement .
  15. Connect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection .
  16. Lower the cab.
  17. Program the ID code.