Fuel Injector Replacement

Special Tools

• EN-47909  Injector Bore and Sleeve Cleaning Kit
• EN-49245  Fuel Injector Seal Installer and Sizer
• EN-50791  Fuel Injector Nozzle Installer
• EN-51105  Fuel Injector Seal Installer

For equivalent regional tools, refer to Special Tools (Diagnostic Tools) and Special Tools (Mechanical Tools) .

1. Remove the fuel injection fuel rail assembly. Refer to Fuel Injection Fuel Rail Assembly Replacement .
2. 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:
   Fig 1: Fuel Rail Insulator Assemblies

   Courtesy of GENERAL MOTORS COMPANY
   • Dry or cracked appearance
   • Flattened or misshapen appearance
3. Disconnect the electrical connections from the fuel injectors.
   Fig 2: Fuel Injector And Retaining Pin

   Courtesy of GENERAL MOTORS COMPANY
4. 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.
5. 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).
   Fig 3: Injectors And Fuel Rail Slot

   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
6. Remove the fuel injector holding clamp (2) from the rear of the fuel injector.
7. Remove and discard the fuel injector O-ring (2) and plastic spacer (1).
   Fig 4: Fuel Injector O-Ring And Plastic Spacer

   Courtesy of GENERAL MOTORS COMPANY
8. Remove and discard the fuel injector seals (3).
9. Clean the exterior of the fuel rail (1) and injectors in solvent.
   Fig 5: Fuel Rail

   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.
10. Using EN-47909  cleaning kit, clean the fuel injector bores and sleeves.
11. 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
12. Replace the fuel rail if any damage is found. Do not attempt to repair a fuel rail.
13. Inspect the fuel pressure sensor (3) for damage.
    CAUTION: Refer to Fastener Caution .
    NOTE: Remove and inspect the fuel pressure sensor only if the sensor is suspect.
    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 (24 lb ft).
    8. Connect the harness connector to the fuel pressure sensor.
14. Inspect the fuel injectors for the following conditions:
    Fig 6: Fuel Injector Connector

    Courtesy of GENERAL MOTORS COMPANY
    • 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)
15. Replace the fuel injector if any damage is found. Do not attempt to repair a fuel injector.
16. Install the a new fuel injector spacer (1).
17. Install the O-ring on the injector.
    NOTE: Lubricate the NEW fuel injector O-ring seals with clean engine oil.
18. Install the fuel injector holding clamp (2) onto the rear of the fuel injector.
    Fig 7: Injectors And Fuel Rail Slot

    Courtesy of GENERAL MOTORS COMPANY
19. Hand install fuel injectors (1) to the fuel rail, carefully aligning the fuel injector tab to the slot in the fuel rail (3).
20. Using EN-50791  installer (3), compress the fuel injector (1) into the fuel rail.
    Fig 8: Fuel Injector And Retaining Pin

    Courtesy of GENERAL MOTORS COMPANY
    NOTE: The injector must be fully installed and properly aligned with the fuel rail before installing the retaining pin.
21. Ensure the fuel injector is fully seated in the fuel rail and install the fuel injector retaining pin (4).
22. 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.
23. Connect the electrical connection to the fuel rail.
    Fig 9: Fuel Rail Harness Connectors

    Courtesy of GENERAL MOTORS COMPANY
24. Connect the fuel rail harness connectors (1) to the fuel injectors.
25. Install EN-49245  protector (2) onto the fuel injector tip. Place a NEW seal (1) on EN-49245  protector.
    Fig 10: Second Recessed Area And NEW Seal

    Courtesy of GENERAL MOTORS COMPANY
    NOTE: Do not use any type of lubricant when installing the NEW seals on the fuel injector tip.
26. Install a seal into the second recessed area (3) of the fuel injector.
27. Compress the seal with your fingers, then resize the seal using the EN-49245  sizer (4).
28. Place a second NEW seal (1) on EN-49245  protector.
29. Install the seal into the first recessed area of the fuel injector.
30. Compress the seal with your fingers, then resize the seal using the EN-49245  sizer (4).
31. Install the fuel injection fuel rail assembly. Refer to Fuel Injection Fuel Rail Assembly Replacement .