GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 1999 🢒 Sonoma Pickup - 2WD 🢒 Engine 🢒 Engine Electrical 🢒 Fuel Injection Fuel Rail Assembly Replacement

Removal Procedure

    Object Number: 161344 Size: SH
  1. Relieve the fuel system pressure. Refer to Fuel Pressure Relief .

    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. Remove the intake manifold assembly. Refer to Intake Manifold Replacement .
  4. Remove the fuel injector electrical connectors by pushing in the wire connector clip and pulling the electrical connector away from the fuel injector.
  5. Remove the fuel feed inlet pipe at the rail (2) . Refer to Quick Connect Fitting(s) Service (Metal Collar) .
  6. Remove the fuel return pipe (3) from the pressure regulator.
  7. Remove the fuel pressure regulator. Refer to Fuel Pressure Regulator Replacement .
  8. Remove the fuel rail attaching bolts.
  9. Lift the fuel rail assembly from the cylinder head.

Installation Procedure

    Object Number: 161344 Size: SH

    Important: Lubricate the fuel injector O-rings with clean engine oil before installation.

  1. Insert the fuel rail into the cylinder head.

    2. 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 fuel rail attaching bolts.

    3. Tighten
    Tighten the fuel rail attaching bolts to 24 N·m(18 lbs ft).

  3. Install the fuel pressure regulator. Refer to Fuel Pressure Regulator Replacement .

    4. Important: Use a backup wrench on the fuel rail return fitting to prevent it from turning.

  4. Install the fuel return pipe (3) to the fuel pressure regulator.

    5. Tighten
    Tighten fuel return pipe nut to 30 N·m (22 lb ft).

  5. Install the fuel feed inlet pipe to the fuel rail (2). Refer to Quick Connect Fitting(s) Service (Metal Collar) .

    6. Important: Rotate the fuel injectors as required to avoid stretching the wire harness.

  6. Install the fuel injector electrical connectors.
  7. Install the intake manifold assembly. Refer to Intake Manifold Replacement .

    8. 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.

  8. Reconnect negative battery cable.
  9. Inspect for fuel leaks through the following steps:
    10. 9.1. Turn the ignition switch to the ON position for two seconds.
    9.2. Turn the ignition switch to the OFF position for ten seconds.
    9.3. Turn the ignition switch to the ON position.
    9.4. Check for fuel leaks.