Fuel Injector Replacement

FUEL INJECTOR REPLACEMENT

TOOLS REQUIRED
J 44639 Fuel Injector Puller

REMOVAL PROCEDURE

IMPORTANT: Refer to Computers and Control Systems Component Views for fuel injector locations. Failure to identify the correct cylinder will result in misdiagnosis.




1. Remove the lower valve cover.

IMPORTANT:
- When the fuel injector pressure lines are removed, debris may fall into the fuel injector inlet fitting. Remove any debris from the inlet fitting of the fuel injector.
- Confirm which side of the banjo washers have the largest outer diameter.

2. Remove the fuel injector return line from fuel injectors.
3. Remove the bolt from the fuel injector bracket.




4. Install J 44639 (2) onto the injector retainer bracket.
5. Install a wrench onto J 44639 (2) and pry away from the fuel injector (1).
6. Remove the fuel injector(s).
7. Remove the copper compression washer from the injector hole if the washer was not removed with the injector.

FUEL INJECTOR CLEANING AND INSPECTION

IMPORTANT: If reusing the old injectors perform the following:

NOTE: The fuel injector must be cleaned with the proper cleaning equipment. DO NOT use abrasive cleaning methods, such as a metallic brush, to remove deposits. Cleaning an injector with improper tools will damage the fuel injector.




1. Use a soft bristle non-metallic brush and top engine cleaner, GM P/N 1052626 (Canadian P/N 993026) or equivalent, to remove any deposits from the nozzle tip (1) and the copper washer sealing area (2) before re-installation.
2. Inspect the fuel injector nozzle tip (1) for any signs of discoloration (dark yellow, tan, or blue) due to excessive heat.
3. Replace the injector if any damage is found.




4. Clean the fuel injector high pressure line.
5. Inspect the fuel injector high pressure line for excessive corrosion or damage to the sealing surfaces (1, 2). Replace the line if any damage is found.

INSTALLATION PROCEDURE




1. If the fuel injector sleeve was pulled from the cylinder head when removing the injector(s), refer to Fuel Injector Sleeve Replacement in Engine-6.6L.
2. Install a NEW O-ring onto the fuel injector(s).
3. Lubricate the O-ring with clean engine oil.
4. Install a NEW copper washer into the fuel injector bore in the cylinder head.
5. Install the fuel injector with injector bracket.

NOTE: Refer to Fastener Notice in Service Precautions.

6. Install the injector bracket bolt.

Tighten
Tighten the bolt to 50 N.m (37 lb ft).




7. Install the return pipe assembly.
8. Install the fuel injector return line to injector eye bolts and washers. Lubricate the washers with diesel fuel prior to installing.

Tighten
Tighten the fuel injector line to injector eye bolts to 16 N.m (12 lb ft).

9. Install the fuel injector return line to cylinder head eye bolts and washers. Lubricate the washers with diesel fuel prior to installing.

Tighten
Tighten the fuel injector return line to cylinder head eye bolts to 17 N.m (12 lb ft).

10. Install the lower valve cover.