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 head 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.  



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Fig. Fig. 1 Using a hammer and brass drift punch, carefully tap the lockring counterclockwise to release the pump

  1. Position the pump in the tank and install the locking ring.
  2.  
  3. Tighten the ring in the same general way in which you loosened it. Do not overtighten it, as this can cause leakage.
  4.  
  5. Install the tank.
  6.  
  7. Connect the negative battery cable.
  8.  

TESTING




WARNING
To perform this procedure, you will need a gauge capable of reading 10-20 psi (69-138 kPa) and the extra length of hose, clamps and fittings necessary to tee the gauge into a 5 / 16 in. (8mm) fuel line. Have a metal container handy to collect any fuel that may spill.

  1. Release the fuel system pressure.
  2.  
  3. Disconnect the fuel supply line at the throttle body.
  4.  
  5. Tee in the gauge between the fuel supply line and the fuel supply nipple on the throttle body, connecting the inlet side of the tee to the fuel supply line and the throttle body side of the tee to the throttle body with a rubber hose and clamps.
  6.  


WARNING
At the beginning of the next step, watch carefully for fuel leaks. Shut the engine off immediately at any sign of leakage.

  1. Start the engine and run it at idle. Read the fuel pressure gauge. Pressure should be 14.5 psi. (100 kPa). If pressure is correct, the pump is okay and you should depressurize the system, remove the gauge, and restore the normal fuel line connections. If the pressure is low, proceed with the next step to test for filter clogging. If the pressure is too high, proceed with Step 6.
  2.  
  3. Stop the engine and then depressurize the system. Remove the gauge tee from the line going into the throttle body and restore the normal connections. Then, tee the gauge into the line going into the fuel filter. Run the test again. If the pressure is now okay, depressurize the system, replace the fuel filter, and restore normal connections. If the pressure is still low, pinch the fuel return hose closed with your fingers. If pressure now increases to above 14.5 psi (100 kPa), replace the fuel pressure regulator. If no change is observed, the problem is either a defective pump or a clogged filter sock in the tank. Make repairs as necessary.
  4.  
  5. With pressure above specification, you must check for a clogged return line that prevents the pressure regulator from controlling fuel pressure properly. Stop the engine, depressurize the system, disconnect the return line at the throttle body and plug it. Connect a length of hose to the throttle body return connection and position the open end into a clean container. Start the engine and repeat the test. If the pressure is now correct, clean out the fuel return line or repair it. Relocate it if it has been pinched or damaged. If the pressure is still too high, replace the pressure regulator.
  6.  

 
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