GM Corvette 1984-1996 Repair Guide

Fuel Rail Assembly

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REMOVAL & INSTALLATION




CAUTION
Observe all applicable safety precautions when working around fuel. Whenever servicing the fuel system, always work in a well ventilated area. Do not allow fuel spray or vapors to come in contact with a spark or open flame. Keep a dry chemical fire extinguisher near the work area. Always keep fuel in a container specifically designed for fuel storage; also, always properly seal fuel containers to avoid the possibility of fire or explosion.

5.7L (VIN 8) Engine

See Figures 1 and 2

  1. Disconnect the negative battery cable.
  2.  
  3. Properly relieve the fuel system pressure, as outlined earlier in this section.
  4.  
  5. Remove the intake plenum, as outlined in Engine & Engine Overhaul of this repair guide.
  6.  


WARNING
Always use a back-up wrench whenever you remove or install fuel line nuts. This will prevent the fuel lines from twisting, warping and/or weakening.

  1. Disconnect the fuel feed and return lines, using a back-up wrench to avoid twisting or warping the fuel lines. Remove and discard the fuel line O-rings.
  2.  
  3. If equipped, disconnect the cold start line, then remove the cold start valve.
  4.  
  5. If equipped, remove the fuel tube bracket bolt.
  6.  
  7. Disconnect the vacuum line from the pressure regulator, then unplug the injector electrical connectors.
  8.  
  9. Loosen the fuel rail retaining bolts, then raise the rail.
  10.  
  11. Remove the intake runners.
  12.  
  13. Remove the fuel rail and injectors.
  14.  
  15. Remove and discard the O-ring seal from the spray tip of each injector.
  16.  



Click image to see an enlarged view

Fig. Fig. 1: Fuel rail assembly mounting-5.7L (VIN 8) engine



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Fig. Fig. 2: Exploded view of the fuel rail, injectors and pressure regulator

To install:
  1. Lightly coat new injector O-rings with clean engine oil, then install on the spray tip of each injector.
  2.  
  3. Installation is the reverse of the removal procedure. Tighten the attaching bolts as follows:
    1. Fuel rail attaching bolts: 15 ft. lbs. (20 Nm).
    2.  
    3. Fuel tube bracket bolt: 25 ft. lbs. (34 Nm).
    4.  
    5. Fuel line nuts: 20 ft. lbs. (27 Nm), using a back-up wrench.
    6.  

  4.  

When attaching the injector electrical connectors, rotate the injectors as necessary to avoid stretching the wire harness.

  1. Connect the negative battery cable, then turn the ignition to the ON position and check for fuel leaks.
  2.  

5.7L (VIN P) Engine

See Figures 3 and 4

  1. Disconnect the negative battery cable and properly relieve fuel system pressure.
  2.  
  3. Remove the fuel rail cover(s).
  4.  
  5. Disengage the quick-connect fittings at the fuel rail feed and return pipes as follows:
    1. Grasp both ends of a connection and twist 1 / 4 turn in each direction to loosen any dirt. Repeat for other fitting.
    2.  
    3. While wearing safety glasses, use compressed air to blow out dirt from the fitting.
    4.  
    5. Insert a fuel line separator tool, into the female connector, then push inward to release the male connector and repeat for the other fitting.
    6.  

  6.  
  7. Disconnect the vacuum line at the pressure regulator.
  8.  
  9. Tag and unplug the injector electrical connectors.
  10.  
  11. Remove the fuel rail attaching bolts and carefully remove the fuel rail assembly along with the injectors, from the top of the intake.
  12.  

The fuel injector lower O-ring uses a nylon collar, called the O-ring backup, which properly positions the O-ring on the injector. Make sure you reinstall the back up, or the sealing O-ring may move on the injector when installing the fuel rail and result in a possible vacuum leak.

  1. Remove and discard the injector lower (brown) O-rings from the spray tip end of each injector. Make sure to save the O-ring backups.
  2.  



Click image to see an enlarged view

Fig. Fig. 3: Fuel rail assembly mounting-5.7L (VIN P and 5) engines



Click image to see an enlarged view

Fig. Fig. 4: Exploded view of the fuel rail, injectors, pressure regulator and fuel pressure connection valve-5.7L (VIN P and 5) engines

To install:
  1. Lightly lubricate new lower (brown) injector O-rings, then install on the spray tip of each injector.
  2.  
  3. Install the fuel rail assembly to the intake manifold. Tighten the attaching bolts to 15 ft. lbs. (20 Nm) for 1992-93 vehicles or to 89 inch lbs. (10 Nm) for 1994-96 vehicles.
  4.  
  5. Rotate the fuel injectors as necessary to avoid stretching the wire harnesses and connect the injector electrical connections.
  6.  
  7. Connect the vacuum line to the pressure regulator.
  8.  
  9. Apply a few drops of clean engine oil to the male ends of the fuel line quick-connect fittings. Engage the fittings by pushing the connectors together until the retaining tabs snap into place. Pull gently on both sides of each fitting to be sure the connection is secure.
  10.  
  11. Tighten the fuel filler cap and connect the negative battery cable.
  12.  
  13. Turn the ignition ON for 2 seconds, OFF for 10 seconds, then ON again and inspect the system for leaks.
  14.  

5.7L (VIN J) Engine

See Figure 5

  1. Disconnect the negative battery cable and properly relieve fuel system pressure.
  2.  
  3. Drain the cooling system into a suitable container.
  4.  
  5. Remove the intake plenum assembly.
  6.  
  7. If not done already when removing the intake plenum, disconnect the fuel feed and return lines from the fuel rail. Remove and discard the old O-rings from the fittings. Disconnect the vacuum line to the pressure regulator.
  8.  
  9. Tag and unplug the fuel injector wire connectors.
  10.  
  11. Remove the bolts securing the fuel rail to the injector housing.
  12.  
  13. Carefully remove the fuel rails making sure not to damage the injector connector terminals or spray tips. Remove the spacers, if equipped. Note the routing of the vacuum hoses around the fuel rail before removing the rail.
  14.  

The fuel injector lower O-ring uses a nylon collar, called the O-ring backup, which properly positions the O-ring on the injector. Make sure you reinstall the back up, or the sealing O-ring may move on the injector when installing the fuel rail and result in a possible vacuum leak.

  1. Remove and discard the injector lower (brown) O-rings from the spray tip end of each injector. Make sure to save the O-ring backups.
  2.  



Click image to see an enlarged view

Fig. Fig. 5: Exploded view of the fuel rail mounting-5.7L (VIN J) engine

To install:
  1. Lightly lubricate new lower (brown) injector O-rings, then install on the spray tip of each injector.
  2.  
  3. Install the fuel rail into the injector housing, routing the vacuum lines in their previous positions around the rail.
  4.  
  5. If equipped, be sure the spacers are properly positioned under the rail mounting bracket.
  6.  
  7. Install the fuel rail bolts and tighten to 20 ft. lbs. (26 Nm).
  8.  
  9. Engage the injector electrical connectors, turning the injectors if necessary to avoid stretching the wire harnesses.
  10.  
  11. Install new O-rings to the fuel feed and return pipes.
  12.  
  13. Connect the fuel feed and return lines with the retaining bolts tightened to 13 ft. lbs. (18 Nm). Temporarily connect the negative battery cable and turn the ignition switch ON for 2 seconds, then OFF for 10 seconds. Cycle the ignition once again to assure proper system pressure, then disconnect the battery negative cable and inspect the fuel system for leaks.
  14.  
  15. Install the plenum assembly. It may be necessary to disconnect the fuel lines for proper installation; if so be sure to relieve the system pressure before disconnecting any fuel fitting.
  16.  
  17. Tighten the fuel filler cap and connect the negative battery terminal.
  18.  
  19. Properly refill the engine cooling system.
  20.  

 
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