GrandPrix, Impala 2006-2008, Monte Carlo 2006-2007

Fuel Pressure Regulator

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The fuel pressure regulator is a diaphragm-operated relief valve with fuel pump pressure on one side and regulator spring pressure and intake manifold vacuum on the other side. The regulator's function is to maintain a constant fuel pressure across the injectors at all times. The pressure regulator compensates for engine load by increasing fuel pressure as engine vacuum drops.

The fuel pressure regulator is serviced as a separate component. When servicing the pressure regulator, make sure that the O-ring back-up, large O-ring, filter screen and small O-ring are properly positioned on the pressure regulator.

Click image to see an enlarged view

Fig. Cutaway view of a typical fuel pressure regulator

The need to work as cleanly as possible cannot be over-emphasized. Even the smallest amount of dirt, if allowed into the fuel pressure regulator and/or the fuel rail, will find its way to the fuel injectors. The nozzle openings of the injectors are very small. Keep hands and tools clean. Clean the areas to be disconnected with a suitable solvent. Carefully cover open fittings and connections to keep out foreign material. Dirt in the injectors almost guarantees a clogged fuel injector and engine performance problems.

Removal & Installation



3.4L (VIN E) Engines
  1. Disconnect the negative battery cable.
  2.  
  3. Relieve the fuel system pressure.
  4.  
  5. Remove the upper intake manifold assembly.
  6.  
  7. Disconnect the vacuum line from the pressure regulator.
  8.  
  9. Remove the regulator retaining screw and remove the retainer bracket. Using a clean shop cloth to catch fuel spillage, carefully pull the regulator from the fuel rail. Twist the regulator slightly while removing to ease removal. Discard the O-ring.

    Click image to see an enlarged view

    Fig. Exploded view of the fuel pressure regulator mounting-3.4L (VIN E) engines

  10.  

To install:

  1. Clean all parts well. DO NOT use shop compressed air to test or clean a fuel pressure regulator. Clean the fuel pressure regulator screen, if necessary. DO NOT immerse the fuel pressure regulator in a solvent bath or it will be damaged.
  2.  
  3. If the filter screen has been contaminated, it should be removed and the pressure regulator replaced.
  4.  
  5. Lubricate a new pressure regulator O-ring with clean engine oil and install on the regulator inlet.
  6.  
  7. Install the fuel return pipe to the regulator.
  8.  
  9. Install a new retainer and spacer bracket into the slot on the fuel rail and install the pressure regulator to the fuel rail. Tighten the fuel return line nut to 13 ft. lbs. (17 Nm).
  10.  
  11. Connect the vacuum line to the pressure regulator and install the retainer screw. Tighten to 76 inch lbs. (8.5 Nm).
  12.  
  13. Inspect and verify that the retainer and spacer bracket is engaged in the slots in the fuel rail. Grasp and pull on the regulator to ensure that it is properly seated.
  14.  
  15. Install the upper intake manifold.
  16.  
  17. Connect the negative battery cable.
  18.  
  19. Inspect for leaks using the following procedure:
    1. Turn the ignition switch to the ON position for 2 seconds.
    2.  
    3. Turn the ignition switch to the OFF position for 10 seconds.
    4.  
    5. Turn the ignition switch to the ON position again.
    6.  
    7. Inspect all areas for fuel leaks.
    8.  

  20.  

3.5L And 3.9L Engine
  1. Disconnect the negative battery cable.
  2.  
  3. Relieve the fuel system pressure.
  4.  
  5. Disconnect the pressure regulator vacuum hose.
  6.  
  7. Remove the regulator assembly retainer clip.
  8.  
  9. Lift and twist the fuel pressure regulator and pull it from its housing. Use a clean shop cloth to catch fuel spillage.
  10.  
  11. Remove and discard the regulator lower O-ring.
  12.  
  13. Remove the regulator assembly filter.
  14.  
  15. Remove and discard the regulator upper O-ring and back-up ring.

    Click image to see an enlarged view

    Fig. Fuel pressure regulator mounting

  16.  

To install:

  1. Clean all parts well. Clean the fuel pressure regulator filter screen. Do not immerse the fuel pressure regulator in a solvent bath to prevent damage to the regulator.
  2.  
  3. Lubricate new O-rings with clean engine oil and install the O-rings on the regulator.
  4.  
  5. Assemble the regulator to its housing and install the retainer clip.
  6.  
  7. Connect the vacuum line.
  8.  
  9. Connect the negative battery cable.
  10.  
  11. Inspect for leaks using the following procedure:
    1. Turn the ignition switch to the ON position for 2 seconds.
    2.  
    3. Turn the ignition switch to the OFF position for 10 seconds.
    4.  
    5. Turn the ignition switch to the ON position again.
    6.  
    7. Inspect all areas for fuel leaks.
    8.  

  12.  

3.8L Engines
  1. Disconnect the negative battery cable.
  2.  
  3. Relieve the fuel system pressure.
  4.  
  5. Clean any dirt from the fuel pressure regulator retaining ring.
  6.  
  7. Remove the vacuum hose from the pressure regulator.
  8.  
  9. Remove the snaprings. Twist the regulator slightly and pull the pressure regulator from the fuel rail. Use a shop towel to catch fuel spillage as the regulator is removed.
  10.  
  11. Remove the O-rings and O-ring back-up.
  12.  

To install:

  1. Clean all parts well. DO NOT use shop compressed air to test or clean a fuel pressure regulator. Clean the fuel pressure regulator screen, if necessary. DO NOT immerse the fuel pressure regulator in a solvent bath or it will be damaged.
  2.  
  3. If the filter screen has been contaminated, it should be removed and the pressure regulator replaced.
  4.  
  5. Lubricate the new pressure regulator O-rings with clean engine oil. Install the O-ring back-up, the large O-ring and then the small O-ring. Install the pressure regulator and secure with the snapring.
  6.  
  7. Attach the vacuum hose.
  8.  
  9. Connect the negative battery cable.
  10.  
  11. Inspect for leaks using the following procedure:
    1. Turn the ignition switch to the ON position for 2 seconds.
    2.  
    3. Turn the ignition switch to the OFF position for 10 seconds.
    4.  
    5. Turn the ignition switch to the ON position again.
    6.  
    7. Inspect all areas for fuel leaks.
    8.  

  12.  

 
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