Special Tools

• EN-47909  Injector Bore and Sleeve Cleaning Kit
• EN-50791  Fuel Injector Nozzle Installer
• EN-51955  Fuel Injector Seal Install/Sizer

For equivalent regional tools, refer to Special Tools .

1. Courtesy of GENERAL MOTORS COMPANY

   Remove and inspect the fuel rail insulator assemblies (1 - 4). Replace the entire assembly if any components show signs of wear or the insulators (4) show the following conditions:

   • Dry or cracked appearance
   • Flattened or misshapen appearance

2. Courtesy of GENERAL MOTORS COMPANY

   Disconnect the electrical connections from the fuel injectors.

3. Use EN-50791  installer (3) to compress the fuel injector (1), and relieve pressure on the retaining pin (2). Remove the fuel injector retaining pin (2). Remove EN-50791  installer once the retaining pin is removed.
4. Remove and DISCARD the fuel injector retainer (2)

5. Courtesy of GENERAL MOTORS COMPANY

   NOTE:

   Support the fuel injector at the widest point. Support the fuel rail along the bottom.

   • DO NOT support or hold the fuel injector by the tip or connector
   • DO NOT tilt or excessively twist the injector during removal

   Remove the injectors (1) from the fuel rail by pulling straight out along the fuel injector axis. Slight rotation of the fuel injector is acceptable as long as excessive force is not applied to the fuel injector tab while engaged in the fuel rail slot (3).

6. Remove the fuel injector holding clamp (2) from the rear of the fuel injector.
7. Remove and DISCARD the direct fuel injector holding done clamp (2)

8. Courtesy of GENERAL MOTORS COMPANY

   Remove and DISCARD the fuel injector fuel rail seal (2) and plastic fuel injector seal spacer (1).

9. Remove and DISCARD the fuel injector nozzle housing seals (3).

10. Courtesy of GENERAL MOTORS COMPANY

    NOTE:

    Do not soak or submerge the fuel rail or injectors in solvent. Do not use solvent on the fuel rail label.

    Clean the exterior of the fuel rail (1) and injectors in solvent.

11. Using EN-47909  cleaning kit, clean the fuel injector bores and sleeves.
12. Inspect the fuel rail and components for the following conditions:
    • Damage, debris, or restrictions to the fuel rail
    • Damage, debris, or restrictions to the fuel ports in the fuel rail
    • Damage to the mounting area for the fuel rail
    • Damage to the fuel rail mounting bolts
    • Damage to the threads on the fuel rail fuel feed fitting
13. Replace the fuel rail if any damage is found. Do not attempt to repair a fuel rail.
CAUTION:

Refer to Fastener Caution .

NOTE:

Remove and inspect the fuel pressure sensor only if the sensor is suspect.

14. Inspect the fuel pressure sensor (3) for damage.
    1. Disconnect the harness connector (2) from the fuel pressure sensor.
    2. Remove the fuel pressure sensor. Dry the fuel pressure sensor bore in the fuel rail with a lint free cloth. The bore should be free of fuel, debris, and burrs.
    3. Lubricate the fuel rail fuel pressure sensor bore with clean engine oil.
    4. Lubricate the threads and sealing area on the fuel pressure sensor with clean engine oil.
    5. Install the fuel pressure sensor hand tight.
    6. Remove the fuel pressure sensor and re-lubricate the bore, threads, and sealing area.
    7. Install the fuel pressure sensor and tighten to 33 N.m (25 lb ft).
    8. Connect the harness connector to the fuel pressure sensor.

15. Courtesy of GENERAL MOTORS COMPANY

    Inspect the fuel injectors for the following conditions:

    • Damage to the fuel injector connector (3)
    • Damage to the fuel injector harness connector
    • Damage to the fuel injector tip (5)
    • Damage to the fuel injector (4)
16. Replace the fuel injector if any damage is found. Do not attempt to repair a fuel injector.
17. Install the a NEW fuel injector seal spacer (1).
18. Lubricate the NEW fuel injector fuel rail seal (2) with one drop of clean engine oil.
19. Install the seal onto the injector.

20. Courtesy of GENERAL MOTORS COMPANY

    Install the NEW fuel injector hold down clamp (2) onto the rear of the fuel injector.

21. Hand install fuel injectors (1) to the fuel rail, carefully aligning the fuel injector tab to the slot in the fuel rail (3).

22. Courtesy of GENERAL MOTORS COMPANY

    NOTE:

    The injector must be fully installed and properly aligned with the fuel rail before installing the retaining pin.

    Using EN-50791  installer (3), compress the fuel injector (1) into the fuel rail.

23. Ensure the fuel injector is fully seated in the fuel rail, and install the NEW fuel injector retainor pin (2).
24. Ensure the fuel injector retaining pin is fully seated in the fuel rail. Remove EN-50791  installer. Repeat process until all fuel injectors are properly installed to the fuel rail.

25. Courtesy of GENERAL MOTORS COMPANY

    Connect the electrical connection to the fuel rail.

26. Connect the fuel rail harness connectors (1) to the fuel injectors.

27. Courtesy of GENERAL MOTORS COMPANY

    NOTE:

    Do not use any type of lubricant when installing the NEW seals on the fuel injector tip.

    Install EN-51955-1  long protector (1) onto the fuel injector tip. Place a NEW fuel injector nozzle housing seal (2) on EN-51955-1  long protector.

28. Using EN-51955-4  pusher (3), install the seal into the second recessed area (4) of the fuel injector, then remove the EN-51955-1  long protector.
29. Compress the seal using EN-51955-3  pre-sizer (5), then resize the seal using the EN-51955-5  sizer (6).
30. Install EN-51955-2  short protector (7) onto the fuel injector tip. Place a second NEW fuel injector nozzle housing seal (8) on EN-51955-2  short protector.
31. Using EN-51955-4  pusher (3), install the seal into the remaining recessed area (9) of the fuel injector, then remove EN-51955-2  short protector.
32. Compress the seal using EN-51955-3  pre-sizer (5), then resize the seal using the EN-51955-5  sizer (6).