Mazda Trucks 1972-1986 Repair Guide

Mechanical Fuel Pump

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See Figure 1

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Fig. Fig. 1: Exploded view of the mechanical fuel pump mounting(1) fuel hoses (2) return line (3) fuel pump assembly. Note the spacer plate between the fuel pump gaskets

All 1986 models use a mechanically driven fuel pump, mounted on the left front of the cylinder head, driven by the camshaft.

TESTING Pressure Test



  1. Disconnect the pump-to-carburetor hose at the carburetor. Connect a pressure gauge.
  2.  
  3. Disconnect the fuel return hose from the pump and plug the pump return and the return port on the carburetor.
  4.  
  5. Run the engine at idle and check the pressure. Pressure should be 3.9-4.4 psi. If not, replace the pump.
  6.  

REMOVAL & INSTALLATION



See Figures 2, 3, 4, 5, 6 and 7

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Fig. Fig. 2: Label all fuel lines connected to the fuel pump ...



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Fig. Fig. 3: ... and clamp off the fuel lines to avoid gasoline spills



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Fig. Fig. 4: Release the spring clamps and slide them down the hose ...



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Fig. Fig. 5: ... then remove the fuel lines



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Fig. Fig. 6: Loosen and remove the two fuel pump mounting bolts ...



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Fig. Fig. 7: ... and pull the fuel pump out of the cylinder head

  1. Disconnect the outlet, inlet and return hoses at the pump.
  2.  
  3. Unbolt and remove the pump and insulator. Discard the gaskets.
  4.  
  5. Installation is the reverse of removal. Use new gaskets coated with sealer.
  6.  

 
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