Fuel Rail and Injectors Cleaning and Inspection

Special Tools

• EN-47909  Injector Bore and Sleeve Cleaning Kit
• EN-49245  Injector Seal Installer Kit
• EN-49247  Injector Retaining Clip Installer

For equivalent regional tools, refer to Special Tools .

Fig 1: View Of Fuel Rail Wiring Harness
Courtesy of GENERAL MOTORS COMPANY
1. Detach and remove the fuel rail wiring harness (1) from the fuel injector rail.
Fig 2: View Of Fuel Injector & Retainer
Courtesy of GENERAL MOTORS COMPANY
2. Using a suitable tool remove the fuel injector to rail retainer (1) from the fuel injector rail by spreading both sides of the fuel injector to rail retainer at the same time.
3. Discard the fuel injector to rail retainer (1).
4. Carefully twist the fuel injector to remove the fuel injector (2) from the fuel injector rail.
Fig 3: View Of Fuel Injector Components
Courtesy of GENERAL MOTORS COMPANY
5. Using a suitable tool remove the fuel injector bushing (3).
6. Discard fuel injector bushing.
7. Remove and discard the following components:
   • Fuel injector O-ring (1).
   • Plastic spacers (2).
   • Fuel injector seals (4).
Fig 4: Identifying Fuel Pressure Sensor
Courtesy of GENERAL MOTORS COMPANY
NOTE:

Do not apply force to the plastic housing of the fuel pressure sensor. Failure to comply will destroy the sensor.

8. Remove the fuel pressure sensor (1) from the fuel injector rail.
NOTE:

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

9. Clean the exterior of the fuel injector rail and fuel injectors with solvent using the injector bore and sleeve cleaning kit EN-47909  injector bore and sleeve cleaning kit.
Fig 5: Identifying Fuel Rail Inspection Areas
Courtesy of GENERAL MOTORS COMPANY
10. Inspect the fuel injector rail (1) 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 or mounting bolt grommets/isolators
    • Damage to the threads on the fuel rail feed fitting
    • Damage to the threads in the fuel pressure sensor bore
    • Damage to the fuel pressure sensor connector, threads, or sealing face
11. If any of the above conditions are found, replace the fuel injector rails. Do not attempt to repair the fuel injector rails.
Fig 6: Identifying Fuel Pressure Sensor
Courtesy of GENERAL MOTORS COMPANY
NOTE:

Do not apply force to the plastic housing of the fuel pressure sensor. Failure to comply will destroy the sensor.

12. Install the fuel pressure sensor (1) to the fuel injector rail.
    NOTE:

    Ensure that the fuel rail threads have been cleaned of any excess fuel or the fuel pressure sensor will NOT seal properly.

    1. Lubricate the threads and the sealing area in the fuel rail with silicon free engine oil. Refer to Adhesives, Fluids, Lubricants, and Sealers for recommended lubricant.
    2. Lubricate the threads and the sealing area on the fuel pressure sensor with silicon free engine oil. Refer to Adhesives, Fluids, Lubricants, and Sealers for recommended lubricant.
    3. Install the fuel pressure sensor to the fuel injector rail and hand tighten.
    4. Remove the fuel pressure sensor from the fuel injector rail and re-lubricate.
    CAUTION:

    Refer to Fastener Caution .

    5. Install the fuel pressure sensor to the fuel injector rail and tighten to 33 N.m (25 lb ft).
Fig 7: Identifying Fuel Injector Components
Courtesy of GENERAL MOTORS COMPANY
13. Inspect the fuel injectors for the following conditions:
    • Damage to the fuel injector connector (1)
    • Damage to the fuel inlet cone (2)
    • Damage to the fuel injector body (3)
    • Damage to the fuel injector tip (4)
14. Replace the fuel injector if any of the above conditions are found. Do not attempt to repair the fuel injectors.
Fig 8: Fuel Injector Bushing
Courtesy of GENERAL MOTORS COMPANY
NOTE:
• The fuel injector bushing (1) is to be installed BEFORE O-ring or backup rings are installed.
• Listen for an audible click to confirm correct installation of the fuel injector bushing
15. Install NEW fuel injector bushing (1) onto injector body. Bushing should seat with a distinct "snap" sound and feel. Ensure bushing is fully seated.
Fig 9: View Of Injector O-Ring & Spacers
Courtesy of GENERAL MOTORS COMPANY
16. Install the NEW white plastic spacer (3) on the fuel injector first.
17. Install the brown plastic spacer (2) second.
18. Lubricate the NEW O-ring (1) with one drop of clean engine oil.
Fig 10: Fuel Injector Wiring Harness Connectors
Courtesy of GENERAL MOTORS COMPANY
CAUTION:

Ensure the fuel injectors are installed in the correct orientation. Improper orientation of the fuel injectors may result in engine misfire and possible engine damage.

19. The right side (bank 1) fuel injector wiring harness connectors (1) should point to the rear of the engine. The left side (bank 2) fuel injector wiring harness connectors (2) should point to the front of the engine.
Fig 11: View Of Injector Assembly
Courtesy of GENERAL MOTORS COMPANY
NOTE:
• Do NOT install the Teflon injector tip/bore seals until AFTER the injectors are installed on the fuel rail.
• Make sure that the fuel injector connectors are placed in the correct position.
20. Holding the largest diameter/body of the injector only, indicated by arrow in graphic, insert the injector assembly (1) into the fuel rail. Ensure correct orientation of the electrical connector (2).
21. Clamp the fuel rail in a bench vise USING SOFT JAWS to aid in holding the rail during the installation of the retainer.
Fig 12: Retainer Installer
Courtesy of GENERAL MOTORS COMPANY
NOTE:
Ensure the retainer is set properly into EN-49247  installer.
• The notch (1) should always face forward
• The fuel injector to fuel rail retainer should be behind the plate (2)
• The tool windows (3) allow for visual alignment
22. Support the fuel injector fuel rail in a vise.
23. Install the fuel injector to fuel rail retainer to the EN-49247  injector retaining clip installer.
Fig 13: Identifying 15-Degree Angle Of Rotation
Courtesy of GENERAL MOTORS COMPANY
NOTE:

Observe the following steps before installing the fuel injector to fuel rail retainer.

24. There is a 15-degree angle of rotation (1) with the fuel injector rail flanges relative to the fuel injector rail. Hold the EN-49247  injector retaining clip installer at a similar angle to aid the correct installation of the fuel injector to fuel rail retainer.
Fig 14: Positioning Retainer Installer
Courtesy of GENERAL MOTORS COMPANY
25. When mounting the EN-49247  injector retaining clip installer to the fuel injector rail, the fuel injector to fuel rail retainer should nearly be touching the electrical connector (2).
26. The base of the EN-49247  injector retaining clip installer should be positioned as shown before squeezing the tool to complete the installation.
Fig 15: Installing Fuel Injector Retainer
Courtesy of GENERAL MOTORS COMPANY
27. Hold the injector bushing (2) and fuel injector rail flanges (1) in alignment.
28. Hold the injector assembly firmly against the fuel injector rail to prevent a gap forming between the fuel injector and the fuel injector rail.
29. Install the fuel injector to fuel rail retainer (3).
Fig 16: Identifying Fuel Rail Flanges
Courtesy of GENERAL MOTORS COMPANY
CAUTION:

Ensure the fuel injector retainer is properly installed. Failure to completely install the retainers may degrade fuel injection system performance or cause system malfunction.

30. Ensure all 3 fuel injector bushing tabs and fuel rail flanges (1) are properly and completely captured by the fuel injector retainer.
31. Repeat the above steps for the remaining fuel injectors until all the fuel injectors are installed and retained in the fuel injector rail.
Fig 17: View Of Fuel Rail Wiring Harness
Courtesy of GENERAL MOTORS COMPANY
32. Install the fuel injector rail wiring harness (1) to the fuel injector rail.
Fig 18: Identifying Fuel Injector Tip & Seals
Courtesy of GENERAL MOTORS COMPANY
NOTE:

Do not use any type of lubricant when installing the NEW seals (2) on the fuel injector tip.

33. Install the long protector (3) of the EN-49245-1  fuel injector seal install/sizer to the fuel injector spray tip covering the first recessed area closest to the tip.
34. Place a NEW seal (2) onto long protector (3) of the EN-49245-1  fuel injector seal install/sizer.
35. Using the pusher (1) of the EN-49245-3  fuel injector seal install/sizer, push the seal (2) into the second recessed area (4) of the fuel injector.
NOTE:

The sizer (5) of the EN-49245-4  fuel injector seal install/sizer is two sided, and either direction will size the seal correctly.

36. Compress the seal (2) with your fingers.
37. Resize the seal (2) using the sizer (5) of the EN-49245-4  fuel injector seal install/sizer.
Fig 19: Identifying Fuel Injector Tip & Seals
Courtesy of GENERAL MOTORS COMPANY
NOTE:

Do not use any type of lubricant when installing the NEW seals (2) on the fuel injector tip.

38. Install the short protector (3) of the EN-49245-2  fuel injector seal install/sizer to the fuel injector tip.
39. Place a NEW seal (2) onto the short protector (3) of EN-49245-2  fuel injector seal install/sizer.
40. Using the pusher (1) of the EN-49245-3  fuel injector seal install/sizer, push the seal (2) into the first recessed area (4) of the fuel injector.
NOTE:

The sizer (5) of the EN-49245-4  fuel injector seal install/sizer is two sided, and either direction will size the seal correctly.

41. Compress the seal (2) with your fingers.
42. Resize the seal (2) using the sizer (5) of the EN-49245-4  fuel injector seal install/sizer.