GM Bonneville/Eighty Eight/LeSabre 1986-1999

Fuel Injector

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See Figure 1

Be careful when servicing or removing the fuel injectors to prevent damage to the electrical connector pins on the injector and nozzle. The fuel injector is serviced as a complete assembly only and should never be immersed in any type of cleaner. Support the fuel rail to avoid damaging other components while removing the injector. Be sure to note that different injectors are calibrated for different flow rates. When ordering new fuel injectors, be sure to order the identical part number that is inscribed on the bottom of the old injector.



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Fig. Fig. 1: Refer to the part number inscribed on the injector to make sure you get the correct part

TESTING



See Figures 2 and 3

The injectors can be tested by installing a "noid light," (a 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 detach 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.  



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Fig. Fig. 2: Detach the fuel injector electrical connector ...



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Fig. Fig. 3: ... then use an ohmmeter to check injector resistance. Compare with specifications from a known good injector

  1. Check between each injector terminal and ground. If continuity exists, replace the injector.
  2.  
  3. Detach 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 9 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.  

REMOVAL & INSTALLATION



See Figures 4, 5, 6, 7, 8 and 9

The fuel injector is serviced as a complete assembly only. If you find that the fuel injectors are leaking, the engine oil may be contaminated with fuel and require changing.

  1. Properly relieve the fuel system pressure.
  2.  
  3. Remove the fuel injector sight shield and/or the air cleaner assembly as necessary.
  4.  
  5. If not already done, disconnect the negative battery cable.
  6.  
  7. Remove the fuel rail from the vehicle, as outlined later in this section.
  8.  
  9. Remove the fuel injector retaining clip(s), then separate the injector from the fuel rail. Discard the injector retaining clips and replace with new ones during installation.
  10.  



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Fig. Fig. 4: After removing the fuel rail, remove the injector retaining clip ...



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Fig. Fig. 5: ... then remove the injector from the fuel rail

  1. Remove and discard the fuel injector upper and lower O-rings, and the lower O-ring back-up.
  2.  



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Fig. Fig. 6: Remove and discard the O-ring from the top of the injector



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Fig. Fig. 7: There is an O-ring and O-ring back-up on the bottom of the injector. Remove and discard the O-ring ...



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Fig. Fig. 8: ... then remove and discard the O-ring back-up. All O-rings should be replaced before installation

Different injectors are calibrated for different flow rates. When ordering new injectors, be sure to order the identical part number that is inscribed on the old injector.



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Fig. Fig. 9: Fuel injector (3), retaining clip (2), upper O-ring (1), lower O-ring (5) and O-ring back-up (4)

To install:

CAUTION
To reduce the risk of fire and personal injury, always install the injector O-rings in the proper position. If the upper and lower O-rings are different colors (black and brown, for example), be sure to install the black O-ring in the upper position and the brown O-ring in the lower position. The O-rings are of the same size, but are made of different materials.

The fuel injector lower O-ring uses a nylon collar, called the O-ring back-up, to properly position the O-ring on the injector. Be sure to install the O-ring back-up, or the sealing O-ring may move on the injector when installing the fuel rail. This can result in a vacuum leak and driveability problems will occur.

  1. Lubricate the new O-ring seals with clean engine oil and install them on the injector.
  2.  
  3. Assemble a new retainer clip onto the injector.
  4.  
  5. Install the fuel injector into the fuel rail socket with the electrical connections facing outwards.
  6.  
  7. Rotate the injector retaining clip to the locked position.
  8.  
  9. Install the fuel rail assembly.
  10.  
  11. Tighten the fuel filler cap and connect the negative battery cable.
  12.  
  13. With the engine OFF , turn the ignition switch to the ON position for 2 seconds, then turn it to the OFF position for 10 seconds. Again, turn it to the ON position and check for fuel leaks.
  14.  

 
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