Escalade, Suburban, Tahoe, Yukon, Denali, DenaliXL, YukonXL 1999-2005

Fuel Injectors

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Removal & Installation



4.3L, 5.0L & 5.7L Engines
With Central Sequential Fuel Injection (Csfi)
  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Relieve the fuel system pressure.
  4.  
  5. Remove or disconnect the following:
    NOTE
    Each injector is calibrated. When replacing the fuel injectors, be sure to replace it with the correct injector.



    Negative battery cable
     
    Electrical connection
     
    Fuel feed and return hoses from the engine fuel pipes
     
    Upper manifold assembly
     
    Poppet nozzle out of the casting socket
     
    Fuel meter body by releasing the locktabs

    Click image to see an enlarged view

    Fig. Exploded view of the CSFI fuel meter body assembly

     



    Lower hold-down plate and nuts
     

  6.  
  7. While pulling the poppet nozzle tube downward, push with a small prytool down between the injector terminals and remove the injectors.

    Click image to see an enlarged view

    Fig. Exploded view of the fuel injector assembly-CSFI systems

  8.  

To install:

  1. Lubricate the new injector O-ring seats with engine oil.
  2.  
  3. Install or connect the following:
    CAUTION
    To reduce the risk of fire or injury ensure that the poppet nozzles are properly seated and locked in their casting sockets



    O-rings on the injector
     
    Fuel injector into the fuel meter body injector socket
     
    Lower hold-down plate and nuts. Torque the nuts to 27 inch lbs. (3 Nm).
     
    Fuel meter body assembly into the intake manifold. Torque the fuel meter bracket retainer bolts to 88 inch. lbs. (10 Nm).
     



    Fuel meter body into the bracket and lock all the tabs in place
     
    Poppet nozzles into the casting sockets
     
    Electrical connections
     
    New O-ring seals on the fuel return and feed hoses
     
    Fuel feed and return hoses. Torque the fuel pipe nuts to 22 ft. lbs. (30 Nm).
     
    Negative battery cable
     

  4.  
  5. Turn the ignition ON for 2 seconds and then turn it OFF for 10 seconds. Again turn the ignition ON and check for leaks.

    Manifold plenum
     

  6.  

With Multi-Port Fuel Injection (MFI)
  1. Before servicing the vehicle, refer to the Precautions section.
    NOTE
    Use care when removing the injectors to prevent damage to the electrical connector pins on the injector and the nozzle. The fuel injector is serviced as a complete assembly only. Since the injector is an electrical component, it should not be immersed in any type of cleaner.

  2.  
  3. Relieve the fuel system pressure.
  4.  
  5. Remove or disconnect the following:

    Negative battery cable
     
    Intake manifold plenum
     
    Fuel rail assembly
     
    Wiring harness
     
    Injector clip and discard it
     
    Injector O-ring seals from both ends of the injector. Save the O-ring backups for use on reassembly

    Click image to see an enlarged view

    Fig. Exploded view of the fuel rail assembly-MFI systems



    Click image to see an enlarged view

    Fig. Exploded view of the fuel injector assembly-MFI systems

     

  6.  

To install:

  1. Install or connect the following:

    O-ring backups before installing the O-rings
     

  2.  
  3. Lubricate the new injector O-rings with clean engine oil

    O-ring to injector assembly
     
    Fuel injector into the fuel rail injector socket with the electrical connectors facing outward
     
    New injector retaining clips on the injector fuel rail assembly by sliding the clip into the injector groove as it snaps onto the fuel rail
     
    Fuel rail assembly
     
    Manifold plenum
     
    Wiring harness
     
    Negative battery cable
     

  4.  

4.8L, 5.3L & 6.0L Engines
  1. Relieve the fuel system pressure.
  2.  
  3. Remove or disconnect the following:

    Negative battery cable
     
    Engine sight shield bolts and bracket
     
    Accelerator control and cruise control cables from the cable bracket and throttle body
     
    Upper engine wire harness retainer nut
     
    Evaporative Emission (EVAP) purge valve harness connector
     

  4.  
  5. Position the upper engine wire harness aside
  6.  
  7. Tag the injector connectors for identification, then pull the top part of the injector connector up. Do not pull the top part of the connector past the top of the white portion.
  8.  
  9. Push the tab on the lower side of the injector connector to release the connect from the injection. Perform these steps on each injector connector.
  10.  
  11. Remove or disconnect the following:
    NOTE
    Use care in removing the fuel injectors in order to prevent damage to the electrical connector pins on the injector and to prevent damage to the nozzle. Service the fuel injector as a complete assembly only. The fuel injector is an electrical component. DO NOT immerse the fuel injector in any type of cleaner.



    Fuel feed and return pipes from the fuel rail
     
    Fuel pressure regulator vacuum line
     
    Crossover tube-to-right fuel rail retainer screw
     
    Fuel rail attaching bolts and fuel rail
     



    Click image to see an enlarged view

    Fig. Fuel injector-4.8L, 5.3L and 6.0L engines



    Click image to see an enlarged view

    Fig. Fuel rail assembly-4.8L, 5.3L and 6.0L engines



    Injector retainer clip. Insert the fork of a fuel injector assembly removal tool behind the injector connector between the fuel rail pod and the 3 protruding retaining clip ledges. Use a prying motion while inserting the tool in order to force the injector out of the fuel rail pod.
     
    Injector retainer clip
     
    Injector O-ring seals from both ends of the injector. Discard the O-ring seals.
     

  12.  

To install:


NOTE
When ordering new fuel injectors, be sure to order the correct injector for the application being serviced. The fuel injector assembly is stamped with a part number identification.

  1. Lubricate the new injector O-ring seals with clean engine oil.
  2.  
  3. Install or connect the following:

    New injector O-ring seals on the injector
     
    New retainer clip on the injector
     

  4.  
  5. Push the fuel injector into the fuel rail injector socket with the electrical connector facing outward. The retainer clip locks on to a flange on the fuel rail injector socket.
  6.  
  7. Remove the crossover tube-to-right fuel rail retainer, then remove the crossover tube.
  8.  
  9. Replace the crossover tube O-ring with a new, lubricated one.
  10.  
  11. Install or connect the following:

    Crossover tube and loosely install the retainer
     
    Fuel rail to the intake manifold
     
    Apply a 0.020 in. (5mm) band of threadlock to the fuel rail retaining bolts
     
    Fuel rail bolts and tighten to 89 inch lbs. (10 Nm)
     
    Crossover pipe retainer and tighten to 34 inch lbs. (3.8 Nm)
     
    Fuel pressure regulator vacuum line
     
    Fuel feed and return pipes
     
    Fuel injector electrical connectors, as tagged. Rotate the injectors as necessary to avoid stretching the wire harness.
     
    Upper engine wire harness
     
    EVAP purge solenoid electrical connector
     
    Upper engine wire harness retainer nut and tighten to 49 inch lbs. (5.5 Nm)
     
    Accelerator control and cruise control cables
     
    Engine sight shield mounting bracket and bolts
     

  12.  
  13. Tighten the fuel cap.
  14.  
  15. Connect the negative battery cable.
  16.  
  17. Turn the ignition ON for 2 seconds.
  18.  
  19. Turn the ignition OFF for 10 seconds.
  20.  
  21. Turn the ignition ON .
  22.  
  23. Inspect for fuel leaks.
  24.  
  25. Install the engine sight shield. Tighten the engine sight shield bolts to 89 inch lbs. (10 Nm)
  26.  

8.1L Engine
  1. Relieve the fuel system pressure.
  2.  
  3. Remove or disconnect the following:

    Negative battery cable
     
    Engine sight shield nuts and bracket
     
    Alternator harness connector
     
    Evaporative Emission (EVAP) purge valve harness connector
     
    Throttle Position (TP) sensor electrical connector
     
    Electronic Throttle Control (ETC) electrical connector
     
    Upper engine wire harness bracket studs, and position the harness aside
     

  4.  
  5. Tag the injector connectors for identification, then pull the top part of the injector connector up. Do not pull the top part of the connector past the top of the white portion.
  6.  
  7. Push the tab on the lower side of the injector connector to release the connect from the injector. Perform these steps on each injector connector.
  8.  
  9. Remove or disconnect the following:
    NOTE
    Use care in removing the fuel injectors in order to prevent damage to the electrical connector pins on the injector and to prevent damage to the nozzle. Service the fuel injector as a complete assembly only. The fuel injector is an electrical component. DO NOT immerse the fuel injector in any type of cleaner.



    Fuel feed and return pipes from the fuel rail
     
    Fuel pressure regulator vacuum line
     
    Fuel rail attaching bolts and fuel rail
     



    Injector retainer clip. Insert the fork of a fuel injector assembly removal tool behind the injector connector between the fuel rail pod and the 3 protruding retaining clip ledges. Use a prying motion while inserting the tool in order to force the injector out of the fuel rail pod.
     
    Injector retainer clip
     
    Injector from the fuel rail pod
     
    Injector O-ring seals from both ends of the injector. Discard the O-ring seals.
     

  10.  

To install:


NOTE
When ordering new fuel injectors, be sure to order the correct injector for the application being serviced. The fuel injector assembly is stamped with a part number identification.

  1. Lubricate the new injector O-ring seals with clean engine oil.
  2.  
  3. Install or connect the following:

    New injector O-ring seals on the injector
     
    New retainer clip on the injector
     

  4.  
  5. Push the fuel injector into the fuel rail injector socket with the electrical connector facing outward. The retainer clip locks on to a flange on the fuel rail injector socket.
  6.  
  7. Install or connect the following:

    Fuel rail to the intake manifold
     
    Apply a 0.020 (5mm) band of threadlock to the fuel rail retaining bolts
     
    Fuel rail bolts and tighten to 106 inch lbs. (12 Nm)
     
    Fuel pressure regulator vacuum line
     
    Fuel feed and return pipes
     
    Fuel injector electrical connectors, as tagged. Rotate the injectors as necessary to avoid stretching the wire harness
     
    Upper engine wire harness bracket
     
    Retainer studs to the upper engine wire harness and tighten the nut to 89 inch lbs. (10 Nm)
     
    Alternator electrical connector
     
    EVAP purge solenoid electrical connector
     
    TP and ETC sensor connectors
     
    Engine sight shield mounting bracket and bolts
     

  8.  
  9. Tighten the fuel cap.
  10.  
  11. Connect the negative battery cable.
  12.  
  13. Turn the ignition ON for 2 seconds.
  14.  
  15. Turn the ignition OFF for 10 seconds.
  16.  
  17. Turn the ignition ON .
  18.  
  19. Inspect for fuel leaks.
  20.  
  21. Install the engine sight shield. Tighten the engine sight shield bolts to 89 inch lbs. (10 Nm).
  22.  

 
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