GM: Electra/Park Avenue/Ninety-Eight 1990-1993

Electric Fuel Pump

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Fig. Fig. 1 Fuel tank unit with electric fuel pump

FUEL PRESSURE CHECK



  1. Connect pressure gauge J 34730-1, or equivalent, to fuel pressure test point on the fuel rail. Wrap a rag around the pressure tap to absorb any leakage that may occur when installing the gauge.
  2.  
  3. Turn the ignition on and check that pump pressure is 41-47 psi.
  4.  
  5. Start the engine and allow it to idle. The fuel pressure should drop 3-10 psi due to the lower manifold pressure.
  6.  

The idle pressure will vary somewhat depending on barometric pressure. Check for a drop in pressure indicating regulator control, rather than specific values.

  1. If the fuel pressure drops, check the operation of the check valve, the pump coupling connection, fuel pressure regulator valve and the injectors. A restricted fuel line or filter may also cause a pressure drop. To check the fuel pump output, restrict the fuel return line and run 12 volts to the pump. The fuel pressure should rise to approximately 75 psi with the return line restricted.
  2.  
  3. Before attempting to remove or service any fuel system component, it is necessary to relieve the fuel system pressure.
  4.  

REMOVAL & INSTALLATION



  1. Disconnect the negative battery cable.
  2.  
  3. Relieve the fuel system pressure.
  4.  
  5. Raise and safely support the vehicle with jackstands.
  6.  
  7. Safely drain and remove the fuel tank assembly as outlined in the `Fuel Tank' removal procedures in this Section.
  8.  
  9. Turn the fuel pump cam lock ring counterclockwise and lift the assembly out of the tank.
  10.  
  11. Remove the fuel pump from the level sensor unit as follows:
  12.  
    1. Pull the pump up into the attaching hose or pulsator while pulling outward away from the bottom support.
    2.  
    3. Take care to prevent damage to the rubber insulator and strainer during removal.
    4.  
    5. When the pump assembly is clear of the bottom support, pull the pump out of the rubber connector for removal.
    6.  


To install:

  1. Replace any attaching hoses or rubber sound insulator that show signs of deterioration.
  2.  
  3. Push the fuel pump into the attaching hoses and install the pump/sensor assembly into the tank. Always use a new O-ring seal. Be careful not to fold over or twist the strainer when installing the sensor unit. Also, make sure the strainer does not block full travel of the float arm.
  4.  
  5. Install the cam lock and turn clockwise to lock.
  6.  
  7. Install the fuel tank as outlined in this Section.
  8.  
  9. Pour 4 gallons of fuel into the tank and check for fuel leaks.
  10.  

 
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