Roadmaster 1992

Fuel Rail (Supply Manifold) & Injectors

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Removal & Installation




CAUTION
Remove the fuel tank cap and properly relieve the fuel system pressure before performing any work on the fuel system or fuel system related components. After the pressure has been released a small amount of fuel may be released when servicing a component. In order to reduce the risk of injury cover the component with a shop towel before disconnection. This will catch any fuel that may leak out. Properly dispose of the shop towel.

Use care in removing the injector to prevent damage to 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. The fuel injector is an electrical component and should not be immersed in any type of cleaner.

  1. Before servicing the vehicle, refer to the Precautions Section.
    NOTE
    Disconnecting the negative battery cable on some vehicles may interfere with the functions of the on-board computer systems and may require the computer to undergo a relearning process, once the negative battery cable is reconnected.


    NOTE
    If working near and/or around the SRS system and components, be sure to properly disable the SRS system. See disarming/arming the SRS system.

  2.  
  3. Disconnect the negative battery cable.
  4.  
  5. Properly relieve the fuel system pressure.
  6.  
  7. Raise the hood, install fender covers and remove the air cleaner assembly.
  8.  
  9. Disconnect electrical connector to injector by squeezing on the tabs and pulling straight up.
  10.  
  11. Remove the fuel meter cover assembly.
  12.  
  13. With the fuel meter cover gasket in place to prevent damage to the casting, use a suitable dowel rod and lay the dowel rod on top of the fuel meter body.
  14.  
  15. Insert a suitable pry tool into the small lip of the injector and pry against the dowel rod lifting the injector straight up.
  16.  
  17. Remove the injector from the fuel meter body. Remove the small O-ring at the bottom of the injector cavity. Be sure to discard both O-rings.

    Click image to see an enlarged view

    Fig. Fuel injector removal-1991-1993



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    Fig. TBI unit and related components-1991-1993



    Click image to see an enlarged view

    Fig. Fuel injector and related components-1991-1993



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    Fig. Fuel injector identification-1991-1993

  18.  

To install:


NOTE
Be sure to use new fasteners, as required.


NOTE
Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread sealer are identified. Do not use paints, lubricants or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners.

  1. Lubricate the new small O-ring with automatic transmission fluid. Push the new O-ring on the nozzle end of the injector, pressing the O-ring up against the injector fuel filter.
  2.  
  3. Install a new steel backup washer in the recess of the fuel meter body.
  4.  
  5. Lubricate the new large O-ring with clean engine oil. Install the new O-ring directly above the backup washer, pressing the O-ring down into the cavity recess. The O-ring is installed properly when it is flush with the fuel meter body casting surface.
    NOTE
    Do not attempt to reverse the installation of the large O-ring procedure. Install the backup washers and O-rings before the injector is located in the cavity or improper seating of the large O-ring could cause a fuel leak.

  6.  
  7. Install the injector by using as pushing and twisting motion to center the nozzle O-ring in the bottom of the injector cavity and aligning the raised lug on the injector base with the notch cast into the fuel meter body.
  8.  
  9. Push down on the injector making sure it is fully seated in the cavity. The injector is installed correctly when the lug is seated in the notch and the electrical terminals are parallel to the throttle shaft in the throttle body.
  10.  
  11. Install the fuel meter cover. Install the injector electrical connector and all electrical and vacuum lines. Install the air cleaner assembly.
  12.  
  13. With the engine OFF and the ignition ON check for fuel leaks.
  14.  
  15. Using the GM diagnostic scan tool or aftermarket equivalent reprogram the necessary systems and components. Be sure to follow the scan tool manufacturer-s directions.
  16.  

 
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