Nissan Z - ZX 1970-1988 Repair Guide

Electric Fuel Pump

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CAUTION
Never smoke when working around gasoline! Avoid all sources of sparks or ignition. Gasoline vapors are EXTREMELY volatile!

The 1975-83 models are equipped with one electric fuel pump mounted near the fuel tank and the right rear wheel. On 1984 and later models, the fuel pump is mounted in the gas tank.

REMOVAL & INSTALLATION



1975 Models
  1. Disconnect the negative battery cable.
  2.  
  3. Remove the inlet hose at the fuel strainer. Remove the outlet hose at the pump and drain the remaining fuel into a suitable container.
  4.  
  5. Disconnect both electrical connections at the pump.
  6.  
  7. Remove the mounting bolts and the pump from the bracket.
  8.  
  9. To install, reverse the removal procedures.
  10.  

1976-79 Models
  1. Disconnect the negative battery cable.
  2.  
  3. Disconnect the wiring harness to the cold start valve.
  4.  
  5. Using two jumper wires from the battery, energize the cold start valve for 2-3 seconds to relieve pressure in the fuel system.
  6.  


WARNING
Be careful not to short the two jumpers together.

  1. Raise and support the rear of the vehicle on jackstands. Have a can and a rag handy to catch any spilled fuel.
  2.  
  3. Clamp the hose between the fuel tank and the fuel pump.
  4.  
  5. Loosen the hose clamps on the fuel lines at both ends of the pump and remove the lines from the pump.
  6.  
  7. Remove the retaining screws and the fuel pump bracket.
  8.  
  9. Disconnect the fuel pump harness connector. On the 280 Z models, roll back the carpet behind the passenger seat to reach the connector. On 280 Z, 2+2 models, remove the rear seat and harness cover, then disconnect the wiring. On ZX models, remove the mat in the luggage compartment and disconnect the harness connector at the rear of the compartment.
  10.  
  11. Pull the harness through the rubber grommet in the floor and remove the fuel pump.
  12.  
  13. To install the fuel pump, reverse the removal procedures.
  14.  

1980-83 Models

See Figures 1 and 2

  1. To reduce the fuel line pressure to zero, perform the following:
    1. On 1980-81 models, start the engine and remove the fuel pump relay No. 2, while the engine is running.
    2.  
    3. On 1982-83 models, lift the rear floor mat and disconnect the fuel pump connector while the engine is running.
    4.  
    5. After the engine stalls, crank the engine with the starter 2-3 times. Turn the ignition OFF .
    6.  

  2.  
  3. Disconnect the negative battery cable.
  4.  



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Fig. Fig. 1: Fuel pump relay location in engine compartment



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Fig. Fig. 2: Electric fuel pump-1980-83 models

  1. Remove the luggage compartment mat. Disconnect the fuel pump harness wiring at the connector at the rear of the compartment. Push the wires and grommet through the floor.
  2.  
  3. Raise and support the rear of the vehicle on jackstands.
  4.  
  5. Clamp the hose between the fuel tank and the pump.
  6.  
  7. Loosen the fuel line clamps and disconnect the hoses from the pump.
  8.  

Have a metal container ready to catch the fuel which will spill from the lines.

  1. Remove the pump bracket-to-body bolts and the pump.
  2.  
  3. To install, reverse the removal procedures.
  4.  

1984-88 Models

See Figures 3 and 4

  1. Refer to the Fuel Tank removal and installation procedures later in this section, and remove the fuel tank.
  2.  
  3. Using a brass drift and a mallet, loosen the retaining ring at the top of the fuel tank.
  4.  
  5. Lift the fuel pump assembly from the fuel tank.
  6.  



Click image to see an enlarged view

Fig. Fig. 3: The fuel pump harness is accessible from inside the vehicle



Click image to see an enlarged view

Fig. Fig. 4: Fuel pump and other fuel tank components-1984-88 models

  1. To install, reverse the removal procedures. Run the engine and check for leaks. DO NOT overtighten the hose clamps and damage the hoses.
  2.  

TESTING



1975-78 Models
FUNCTIONAL TEST
  1. Disconnect the cable from the "S'' terminal of the starter motor solenoid.
  2.  
  3. Unplug the cold start valve wiring harness connector.
  4.  
  5. Turn the ignition key to START . You should be able to hear the fuel pump running. If not, check the wiring circuits and fuses. If the circuits and fuses are okay, replace the pump.
  6.  

PRESSURE TEST
  1. Reduce the fuel line pressure to zero.
  2.  
  3. Connect a pressure gauge into the fuel line in the engine compartment between the fuel tube and the fuel filter outlet hose.
  4.  
  5. Disconnect the wire from the "S'' terminal of the starter motor solenoid.
  6.  
  7. Connect the negative battery cable.
  8.  
  9. Turn the ignition key to START .
  10.  
  11. Pressure should be approximately 36 psi (245 kPa).
  12.  
  13. If not, replace the pressure regulator and repeat the tests. If the pressure is still not correct, check all fuel lines for kinks or blockage, then replace the pump, as necessary.
  14.  

1979-88 Models
FUNCTIONAL TEST
  1. Disconnect either the wire to the alternator "L'' terminal or the oil pressure switch connector.
  2.  
  3. Turn the ignition key to START . You should be able to hear the fuel pump running. If not, check the wiring circuits and fuses; if they are in order, replace the fuel pump.
  4.  

PRESSURE TEST
  1. Reduce the fuel pressure to zero.
  2.  

For 1979 models, follow Steps 1-3 of the 1976-79 fuel pump removal and installation procedure. For 1980-83 models, follow Step 1 of the 1980-83 fuel pump replacement procedure. For 1984-88 models, follow Step 1 of the Fuel Tank removal procedure.

  1. On 1979 models, connect the negative battery cable.
  2.  
  3. Connect a fuel pressure gauge into the fuel line in the engine compartment between the fuel pipe and the fuel filter outlet hose.
  4.  
  5. Start the engine and read the fuel pressure. On non-turbo models the pressure should be approximately 30 psi (204 kPa) at idle and approximately 37 psi (252 kPa) (except turbo) or 44 psi (299 kPa) for turbo models at any speed above idle.
  6.  
  7. If the pressure is incorrect, replace the pressure regulator, following the replacement procedure given later in this section. After replacement of the regulator, repeat the pressure test. If still incorrect, check the fuel lines for kinks or blockage and replace the pump as necessary.
  8.  

 
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