GM Buick/Oldsmobile/Pontiac/Full-Size 1975-1990 Repair Guide

Throttle Body

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See Figures 1, 2 and 3

REMOVAL & INSTALLATION



  1. Allow the fuel pressure to bleed off.
  2.  
  3. Disconnect the negative battery cable.
  4.  
  5. Remove the air cleaner assembly, noting and labeling the vacuum and electrical connections.
  6.  
  7. Disconnect and label the electrical connectors at the TBI unit.
  8.  
  9. Disconnect the throttle cable at the TBI unit.
  10.  
  11. Disconnect the fuel feed and return lines.
  12.  
  13. Unbolt and remove the TBI unit.
  14.  
  15. Installation is the reverse of removal.
  16.  



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Fig. Fig. 1: TBI unit

INJECTOR REPLACEMENT



  1. Allow the fuel pressure to bleed off and disconnect the negative battery cable.
  2.  
  3. Remove the air cleaner assembly.
  4.  
  5. Squeeze the two tabs of the injector connector and pull straight up.
  6.  
  7. Remove the fuel meter cover.
  8.  
  9. With the fuel meter cover gasket in place to prevent damage to the casting, use a screwdriver to lift the injector carefully until it is free from the fuel meter body.
  10.  



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Fig. Fig. 2: Removing fuel injector

  1. Remove the small O-ring from the nozzle end of the injector. Carefully rotate the injector back and forth and remove the filter from the base of the injector.
  2.  
  3. Remove and discard the fuel meter cover gasket.
  4.  
  5. Remove the large O-ring and steel back-up washer from the top of the counterbore of the fuel meter body injector cavity.
  6.  

To install:
  1. Install the fuel injector nozzle filter on the nozzle end of the fuel injector. Use a twisting motion to position the filter against the base of the injector.
  2.  
  3. Lubricate a new small O-ring with automatic transmission fluid. Push the O-ring on the nozzle end of the injector until it presses against the injector fuel filter.
  4.  
  5. Install the steel backup washer in the top counterbore of the fuel meter body injector cavity.
  6.  
  7. Lubricate a new large O-ring with automatic transmission fluid and install it directly over the backup washer. Be sure the O-ring is seated properly in the cavity and is flush with the top of the fuel meter casting surface.
  8.  
  9. Install the injector in the cavity, aligning the raised lug on the injector base with the cast-in notch in the fuel meter body cavity. Push down on the injector until it is fully seated in the cavity.
  10.  
  11. Install the fuel meter cover. Thread locking compound must be used on the threads.
  12.  
  13. Install the injector electrical connector.
  14.  
  15. Install the air cleaner and reconnect the negative battery cable.
  16.  



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Fig. Fig. 3: Fuel injector components

 
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