Toyota Tercel 1984-1994 Repair Guide

Mechanical Fuel Pump

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REMOVAL & INSTALLATION



See Figures 1, 2, 3 and 4

The pump is located on the side of the cylinder head. To remove the fuel pump:

  1. Disconnect the negative battery cable. With the engine cold and the key removed from the ignition, label and disconnect the fuel hoses from the fuel pump. Plug the lines as soon as they are removed.
  2.  


CAUTION
The fuel system contains gasoline. Wear eye protection and contain spillage. Observe "no smoking/no open flame'' precautions. Have a Class B-C (dry powder) fire extinguisher within arm's reach at all times.

  1. Remove the mounting bolts holding the pump.
  2.  
  3. Remove the fuel pump.
  4.  
  5. Cover the fuel pump mounting face on the cylinder head.
  6.  

To install:
  1. Always use a new gasket. Place the fuel pump in position and install the two bolts. Tighten evenly to 13 ft. lbs. (18 Nm).
  2.  
  3. Connect the hoses to the fuel pump.
  4.  
  5. Start the engine and check for leaks.
  6.  



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Fig. Fig. 1: Label the hoses before disconnecting them. Most clamps can be loosened by pressing the tangs together and sliding the clamp upwards



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Fig. Fig. 2: Twist and pull, to remove the hoses from the fuel pump



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Fig. Fig. 3: The fuel pump is usually secured by two nuts or bolts



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Fig. Fig. 4: Pull the fuel pump out of it's mounting boss on the cylinder head

TESTING



See Figures 5, 6, 7, 8, 9, 10 and 11

Before performing any checks on the fuel pump, two conditions must be met. First, the pump must be internally "wet''. Run a small amount of fuel into the pump so that the check valves will seal properly when tested. Dry valves may not seal and will yield false test results.

Hold the pump without blocking either pipe and operate the pump lever, noting the amount of force needed to move it. This is the reference point for all the tests. Do not apply more than this amount of force to the lever during the testing. Excessive force can damage an otherwise usable pump.

  1. Block off the outlet and return pipes with your fingers. Operate the lever. There should be an increase in arm play and it should move freely.
  2.  
  3. Block the inlet port with your finger and operate the lever. The arm should lock when the normal amount of force is applied.
  4.  
  5. The diaphragm is checked by blocking the inlet, outlet and return pipes. When normal force is applied to the lever, the lever should lock and not move. Any lever motion indicates a ruptured diaphragm. This is a common cause of poor fuel mileage and poor acceleration since the correct amount of fuel is not being delivered to the carburetor.
  6.  

The fuel pump must pass all three of these tests to be considered usable. If the pump fails one or more tests, it must be replaced.

  1. Check the oil seal within the pump. Block off the vent hole in the lower part of the pump housing. The lever arm should lock when normal force is applied.
  2.  



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Fig. Fig. 5: Fuel pump used on 3A and 3A-C engines



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Fig. Fig. 6: Fuel pump found on 3E engines



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Fig. Fig. 7: With the return and outlet pipes blocked, the lever should not be locked



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Fig. Fig. 8: The lever should be locked when the inlet pipe is blocked



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Fig. Fig. 9: The pump lever should be locked when all pipes are blocked



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Fig. Fig. 10: The oil seal can be checked by blocking off the vent hole. The pump lever should be locked



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Fig. Fig. 11: The fuel filter and lines should also be checked for leaks and restrictions

 
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