Dodge Omni/Horizon/Rampage 1978-1989 Repair Guide

Electric Fuel Pump

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REMOVAL & INSTALLATION



An electric fuel pump is used with fuel injection systems in order to provide higher and more uniform fuel pressures. It is located in the tank.

  1. Relive the fuel pressure.
  2.  
  3. Disconnect the negative battery cable.
  4.  
  5. Remove the tank from the vehicle.
  6.  
  7. With a soft headed hammer and non-metallic punch, tap the fuel pump lockring counterclockwise to release the pump.
  8.  

To install:

  1. Wipe the seal area of the tank clean and install a new O-ring seal.
  2.  
  3. Replace the filter on the end of the pump if it appears to be damaged.
  4.  
  5. Position the pump in the tank and install the locking ring.
  6.  
  7. Tighten the ring in the same general way in which you loosened it. Do not overtighten it, as this can cause leakage.
  8.  
  9. Install the tank.
  10.  
  11. Connect the negative battery cable.
  12.  



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Fig. Fig. 1 no caption

TESTING




WARNING
To perform this test, you will need a pressure gauge capable of reading pressures above 55 psi (379 kPa). The gauge must have a connection that will fit the fuel rail service valve. The gauge should be compatible with Chrysler part No. C-3292 and the connector fitting compatible with C-4805. You may also need a tee and fittings necessary to tee the gauge into the fuel supply line at the tank, and a 2 gallon container suitable for collecting fuel.

  1. Release the fuel system pressure. Remove the protective cover from the service valve on the fuel rail.
  2.  
  3. Connect the gauge to the pressure tap on the fuel rail. Hold the gauge and have someone start the engine. Run the engine at idle speed in Neutral (manual transaxles) or Park (automatic transaxles).
  4.  
  5. Read the pressure. It should be 53-57 psi. (365-393 kPa). If it is outside the range, take note of it. Stop the engine, depressurize the system, then disconnect the gauge and replace the protective cover. If the pressure is correct, the test is complete. If the pressure is below the range, proceed with the steps following; if it is too high, proceed with Step 7.
  6.  


WARNING
In the next step, note that fuel may drain from the lines as you disconnect them. Make sure all surrounding exhaust system parts are cool and that all sources of ignition are removed from the area. Collect fuel and dispose of it safely.

  1. Connect the gauge into the fuel supply line running between the tank and the filter which is located at the rear of the vehicle.
  2.  


WARNING
Make sure all connections are secure.

  1. Have someone start the engine. Read the pressure gauge. If the pressure has risen more than 5 psi, (34 kPa) replace the filter. If the pressure is now within range:
  2.  
    1. Allow the engine to cool
    2.  
    3. Remove all sources of ignition
    4.  
    5. Depressurize the system
    6.  
    7. Disconnect the gauge from the lines
    8.  
    9. Replace the fuel filter
    10.  
    11. Restore connections
    12.  

  3. If the pressure is still too low, gently and gradually pinch the fuel return line closed as you watch the gauge. If the pressure increases, the fuel pressure regulator is at fault. If there is no change, the problem is either clogging of the filter sock mounted on the pump itself or a defective pump.
  4.  
  5. If the pressure is too high, shut off the engine, allow it to cool, depressurize the system and then disconnect the fuel return hose at the chassis, near the fuel tank. Connect a 3 foot length of hose to the open end of the line running along the chassis. Position the open end of the line into a container suitable for collecting fuel. Have a helper start the engine and check the pressure. If it is now correct, check the in-tank fuel return hose for kinking. If the hose is okay, and the system still exhibits excessive pressure with the tank half full or more, the fuel pump reservoir check valve or aspirator jet may be obstructed and the assembly must be replaced.
  6.  
  7. If the pressure is still too high, shut off the engine, and allow it to cool. Depressurize the system and then reconnect the fuel lines at the rear. Disconnect the fuel return hose at the pressure regulator. Collect all fuel that drains. Then, run the open connection into a large metal container. Connect the fuel gauge back into the fuel rail. Start the engine and repeat the test. If the fuel pressure is now correct, clean a clogged return line or replace pinched or kinked sections of the return line. If no such problems exist, replace the fuel pressure regulator.
  8.  

 
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