GM Service Manual Online
For 1990-2009 cars only

Fuel Injector Replacement Central SFI

Removal Procedure

Notice: Use care in removing the fuel injectors to prevent damage to the electrical connector terminals.

The fuel injector is serviced as a complete assembly only.

Also since the injectors are electrical components, these injectors should not be immersed in any type of liquid solvent or cleaner as damage may occur. Fuel injector cleaning is not recommended.

  1. Disconnect the negative battery cable. Refer to

    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.

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  2. Relieve the fuel system pressure. Refer to Fuel Pressure Relief Procedure .
  3. Remove the Upper Manifold Assembly. Refer to Engine Mechanical.
  4. Remove the Fuel Meter Body Assembly. Refer to Fuel Meter Body Assembly .

Disassemble Procedure

  1. Disassemble the lower hold down plate and the nuts.
  2. While pulling the poppet nozzle tube downward, push with small screwdriver down between the injector terminals until the injector is removed.

Assemble Procedure

Important: Each injector is calibrated for a specific flow rate. Order the correct injector for the application being serviced when replacing the fuel injectors.

  1. Lubricate the new injector O-ring seals with clean engine oil.
  2. Install the O-rings on the injector assembly.
  3. Assemble the Central SFI fuel injector assembly into the fuel meter body injector socket.
  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.

  5. Assemble the lower hold down plate and nuts.
  6. Tighten
    Tighten the nuts to 3.0 N·m (27 lb in).

Installation Procedure

  1. Install the fuel meter body assembly. Refer to Fuel Meter Body Assembly .
  2. Install the upper manifold assembly. Refer to Engine Mechanical.
  3. Connect the negative battery cable.

Fuel Injector Replacement SFI

Removal Procedure

Notice: Use care in removing the fuel injectors in order to prevent damage to the fuel injector electrical connector pins or the fuel injector nozzles. Do not immerse the fuel injector in any type of cleaner. The fuel injector is an electrical component and may be damaged by this cleaning method.

  1. Disconnect the negative battery cable.
  2. Relieve fuel system pressure. Refer to the Fuel Pressure Relief Procedure .
  3. Remove the intake manifold plenum. Refer to Engine Mechanical.
  4. Disconnect the fuel rail assembly. Refer to Fuel Rail Assembly Replacement

Disassemble Procedure


    Object Number: 13106  Size: SH
  1. Disconnect the electrical wiring harness
  2. Remove the injector retainer clip (1) and discard.
  3. Remove the fuel injector assembly (3).
  4. Important: When ordering new fuel injectors, be sure to order the correct injector for the application being serviced.

  5. Remove the injector O-ring seals (2), (4), (5), from both ends of injector and discard. Save the O-ring backups for use on reassembly.

Assembly Procedure


    Object Number: 13106  Size: SH
  1. Ensure that O-ring backups (2), (4), (5), are on injectors before installing new O-rings. Lubricate the new injector O-ring seals with clean engine oil and install on the injector assembly.
  2. Install the fuel injector assembly (3) into the fuel rail injector socket with the electrical connectors facing outward.
  3. Install the new injector retainer clips (1) on the injector fuel rail assembly by sliding the clip into the injector groove as it snaps onto the composite fuel rail.

Installation Procedure

  1. Install the fuel rail assembly. Refer to Fuel Rail Assembly Replacement
  2. Install the intake manifold plenum. Refer to Engine Mechanical.