Toyota Corolla 1970-1987 Repair Guide

Mechanical Fuel Pump

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REMOVAL & INSTALLATION



See Figures 1 through 5

  1. Disconnect the negative battery cable. Remove the air cleaner assembly, if necessary.
  2.  
  3. Disconnect and plug both of the fuel lines form the fuel pump (some models have 3 lines).
  4.  
  5. Unscrew and remove the two fuel pump mounting bolts.
  6.  
  7. Withdraw the fuel pump assembly from the engine block.
  8.  
  9. Installation is in the reverse order of removal.
  10.  

Always use a new gasket when installing the fuel pump
  1. Start the engine and check the pump for any leaks.
  2.  



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Fig. Fig. 1: Cross-section of mechanical fuel pump



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Fig. Fig. 2: Removing the mechanical fuel pump

TESTING



Some vehicles with a carburetor may use an electric, external mount type fuel pump

Fuel pumps should always be tested on the vehicle. The larger line between the pump and tank is the suction side of the system and the smaller line, between the pump and carburetor, is the pressure side. A leak in the pressure side would be apparent because of dripping fuel. A leak in the suction side is usually only apparent because of a reduced volume of fuel delivered to the pressure side.

  1. Tighten any loose line connections and look for any kinks or restrictions.
  2.  
  3. Disconnect the fuel line at the carburetor. Disconnect the distributor-to-coil primary wire. Place a container at the end of the fuel line and crank the engine a few revolutions. If little or no fuel flows from the line, either the fuel pump is inoperative or the line is plugged. Blow through the lines with compressed air and try the test again. Reconnect the line.
  4.  
  5. If fuel flows in good volume, check the fuel pump pressure to be sure the pump is operating properly.
  6.  
  7. Attach a pressure gauge to the pressure side of the fuel line. On cars equipped with a vapor return system, squeeze off the return hose.
  8.  
  9. Run the engine at idle and note the reading on the gauge. Stop the engine and compare the reading with the specifications listed in the Tune-Up Specifications chart found in Engine Electrical in this repair guide. If the pump is operating properly, the pressure will be as specified and will be constant at idle speed. If pressure varies sporadically or is too high/low, the pump should be replaced.
  10.  
  11. Remove the pressure gauge.
  12.  
  13. The following flow test can also be performed:
    1. Disconnect the fuel line from the carburetor. Run the fuel line into a suitable measuring container.
    2.  
    3. Run the engine at idle until there is one pint of fuel in the container. One pint should be pumped in 30 seconds or less.
    4.  
    5. If the flow is below minimum, check for a restriction in the line. The only way to check fuel pump pressure is by connecting an accurate pressure gauge to the fuel line at the carburetor level. Never replace a fuel pump without performing this simple test. If the engine seems to be starving for fuel, check the ignition system first. Also check for a plugged fuel filter or a restricted fuel line before replacing the pump.
    6.  

  14.  



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Fig. Fig. 3: Remove the fuel lines from the fuel pump



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Fig. Fig. 4: The fuel pump is attached to the engine using bolts



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Fig. Fig. 5: Once the bolts are removed, carefully separate the fuel pump from the engine-always replace the gasket upon installation

 
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