GM Corvette 1984-1996 Repair Guide

Fuel Injector(s)

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REMOVAL & INSTALLATION



5.7L (VIN 8) Engine

See Figure 1

  1. Disconnect the negative battery cable.
  2.  
  3. Properly relieve the fuel system pressure.
  4.  
  5. Remove the intake plenum and runners.
  6.  
  7. Remove the fuel rail assembly, as outlined later in this section.
  8.  
  9. Rotate the injector retaining clip to the release position.
  10.  



Click image to see an enlarged view

Fig. Fig. 1: The injector is secured in the fuel rail socket with a metal retaining clip

  1. Remove the injector by pulling it from the fuel rail assembly.
  2.  
  3. Remove and discard the retaining clip, and the O-ring seals from each end of the injector.
  4.  

To install:

Always replace injectors using the identical part number which is inscribed on the old injector.

  1. Lightly lubricate new injector O-rings with clean engine oil, then install onto the injector.
  2.  
  3. Install a new injector retaining clip onto the injector.
  4.  
  5. Install the injector to the fuel rail socket with the electrical connector facing outward.
  6.  
  7. Rotate the injector retaining clip to the locked position/
  8.  
  9. Install the fuel rail.
  10.  
  11. Temporarily connect the negative battery cable. With the engine OFF and the ignition ON , check for fuel leaks. Disconnect the negative battery cable.
  12.  
  13. Install the intake plenum and runners, then connect the negative battery cable.
  14.  

5.7L (VIN P and 5) Engine

See Figure 2

  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.  
  13. Rotate the injector retaining clip to the release position and remove the injector from the fuel rail assembly.
  14.  
  15. Remove and discard the O-ring seals from either side of the injector.
  16.  
  17. Remove and discard the injector retaining clip.
  18.  



Click image to see an enlarged view

Fig. Fig. 2: Pulling the fuel injection from the fuel rail-5.7L (VIN P and 5) engines

To install:
  1. Lubricate the new injector O-rings with clean engine oil and install onto the injector.
  2.  

Always replace injectors using an identical part number as inscribed in the old injector.

Click image to see an enlarged view

Fig. Fig. 3: Always make sure you are using the proper part number when installing a new injector

  1. Fasten a new retainer clip onto the fuel injector and install the injector to the fuel rail assembly. Rotate the injector retaining clip to the lock position.
  2.  
  3. Install the fuel rail assembly to the intake manifold. Tighten the attaching bolts to 15 ft. lbs. (20 Nm).
  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 Figures 4 and 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. 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.  
  15. Remove the injector retaining clip, then remove the injector.
  16.  
  17. Remove and discard the injector O-ring seals.
  18.  



Click image to see an enlarged view

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



Click image to see an enlarged view

Fig. Fig. 5: Installing the fuel injector on the fuel rail

To install:
  1. Lubricate new injector O-rings with engine oil and install the injector with retaining clip onto fuel rail. Make sure the injector wire connection is facing outward and push the injector onto the rail sufficiently to engage the clip with the machined slots on the rail socket.
  2.  

Each injector is calibrated for a specific flow rate and must be replaced with an identical part number.

  1. Install the fuel rail into the injector housing, routing the vacuum lines in their previous positions around the rail.
  2.  
  3. If equipped, be sure the spacers are properly positioned under the rail mounting bracket.
  4.  
  5. Install the fuel rail bolts and tighten to 20 ft. lbs. (26 Nm).
  6.  
  7. Engage the injector electrical connectors, turning the injectors if necessary to avoid stretching the wire harnesses.
  8.  
  9. Install new O-rings to the fuel feed and return pipes.
  10.  
  11. 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.
  12.  
  13. 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.
  14.  
  15. Tighten the fuel filler cap and connect the negative battery terminal.
  16.  
  17. Properly refill the engine cooling system.
  18.  

TESTING



See Figures 6 and 7

The injectors can be tested by installing a 'noid light', (headlamp bulb may work) into the injector electrical connector, which confirms voltage when the light flashes.

  1. Start the engine and listen to each fuel injector individually for a 'clicking' sound.
  2.  
  3. Turn the engine off and disconnect the electrical connector from the injector(s) that did not have a 'clicking' sound.
  4.  
  5. Check the injector for continuity across the terminals. Compare the resistance value to a known good injector. The readings should be similar, if so proceed to the next step. If readings differ greatly, replace the injector.
  6.  



Click image to see an enlarged view

Fig. Fig. 6: Fuel injector testers can be purchased or sometimes rented



Click image to see an enlarged view

Fig. Fig. 7: A noid light can be attached to the fuel injector harness in order to test for injector pulse

  1. Check between each injector terminal and ground. If continuity exists, replace the injector.
  2.  
  3. Disconnect the fuel injector connector and connect a noid light to the wiring harness connector. Crank the engine, while watching the light. Perform this test on at least two injectors before proceeding. If the light does not flash, check the injector power supply and ground control circuitry. If the light flashes proceed to the next step.
  4.  
  5. If the light flashes, remove the fuel rail from the engine and following the procedure below check the injector operation:
    1. Using mechanic's wire, secure the injector to the fuel rail.
    2.  
    3. Place a clear plastic container around each injector.
    4.  

  6.  


CAUTION
Prior to performing this test, all fuel safety precautions must be followed. Make certain the container is approved to handle fuel and is securely positioned around the injector. Do NOT use a glass container. Glass containers can be easily damaged, resulting in a serious fire hazard.

  1. With the help of an assistant or using a remote starter button, crank the engine for 15 seconds while observing the injector operation. The injector should produce a cone shaped spray pattern and all containers should retain equal amounts of fuel.
  2.  
  3. Once the cranking test is complete leave the fuel rail pressurized and observe the injectors for leakage.
  4.  

  1. Replace any injector which is leaking or fails to provide a cone shaped spray pattern when energized.
  2.  

 
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