GM Lumina/Silhouette/Transport APVs 1990-1999 Repair Guide

Fuel Injectors

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REMOVAL AND 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.


WARNING
When removing the injector(s), be careful not to damage the electrical connector pins (on top of the injector), the injector fuel filter and the nozzle. The fuel injector is serviced as a complete assembly ONLY, it is an electrical component and should not be immersed in any kind of cleaner.

It is recommended to replace all gaskets and O-rings on disconnected fuel system components. Read the procedure first to ensure that you will have the necessary parts to complete the repair.

  1. Disconnect the negative battery terminal from the battery. Remove the air cleaner.
  2.  
  3. Properly relieve the fuel system pressure.
  4.  
  5. Unplug the electrical connectors at the injectors by squeezing the two tabs together and pulling it straight up.
  6.  

See Figure 1

Click image to see an enlarged view

Fig. Fig. 1: Carefully pry the injector from the throttle body assembly

  1. Remove the fuel meter cover.
  2.  

When removing the fuel meter cover screws, note the location of the two short screws.

  1. Using a small pry tool and support bar, carefully pry up on the injector until it is free from the fuel meter body.
  2.  
  3. Remove the lower small O-ring from the nozzle end of the injector and discard.
  4.  
  5. Discard the fuel meter cover gasket.
  6.  
  7. Remove the upper, large O-ring from the top of the injector cavity and discard.
  8.  

See Figure 2

Click image to see an enlarged view

Fig. Fig. 2: Exploded view of the injector and O-rings

To install:
  1. Lubricate the new upper (large) O-ring with clean engine oil, and install in the counterbore of the fuel meter body. Make sure it is seated properly.
  2.  


CAUTION
When installing an injector, install the upper O-ring before the injector to ensure proper seating of the O-ring. Reversing these steps could result in a fuel leak and possible fire.

  1. Lubricate the new lower (small) O-ring with clean engine oil, and install on the nozzle end of the injector. Push the O-ring on far enough to contact the filter.
  2.  
  3. Install the fuel injector as follows:
    1. Align the raised lug on the injector base with the notch on the fuel meter body cavity.
    2.  
    3. Push down on the injector until it is fully seated in the fuel meter body.
    4.  

  4.  

The electrical terminals of the injector should be parallel with the throttle shaft.

See Figure 3

Click image to see an enlarged view

Fig. Fig. 3: Firmly press the injector into the throttle body

  1. Install the fuel meter cover assembly.
  2.  
  3. Install the electrical connectors to the injectors.
  4.  
  5. Connect the negative battery cable.
  6.  
  7. Turn the ignition switch to the ON position for 2 seconds then turn to the OFF position for 10 seconds. Again turn the switch to the ON position and check for leaks.
  8.  
  9. Install the air cleaner assembly.
  10.  

TESTING




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.

  1. Ensure that the vehicle's ignition system is operating properly.
  2.  
  3. Perform a fuel pump test to ensure that fuel is getting to the injectors.
  4.  
  5. Remove the air cleaner assembly.
  6.  
  7. Have an assistant crank the engine and observe the fuel injectors.
  8.  
  9. There should be a fuel spray below the injectors, into the throttle body.
  10.  
  11. If there is no fuel spray coming from the injectors, perform the following steps:
    1. Turn the ignition switch OFF .
    2.  
    3. Detach the electrical connector(s) from the fuel injector(s).
    4.  
    5. Attach a suitable test light to the A terminal of each harness and to ground.
    6.  
    7. Crank the engine and observe the test light.
    8.  
    9. If the light blinks, the injector is probably faulty. Replace the injector with a known good one and repeat the tests.
    10.  
    11. If the light fails to blink, there is a problem with the wiring harness or engine control module.
    12.  

  12.  
  13. If fuel sprays from the injector, perform the following steps:
    1. Turn the ignition OFF .
    2.  
    3. Detach the electrical connector(s) from the injector(s).
    4.  
    5. Crank the engine and observe any fuel spray or drip from the injector.
    6.  
    7. If there is no fuel spray or drips from the injectors, the injectors are fine.
    8.  
    9. If fuel spray or drips are visible, the injectors are leaking internally and must be replaced.
    10.  

  14.  

 
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