Suzuki Samurai/Sidekick/Tracker 1986-1998 Repair Guide

Fuel Pump

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REMOVAL & INSTALLATION



See Figure 1

The fuel pump is mounted in the fuel tank, which must be removed to service the fuel pump.

  1. Remove the fuel tank from the vehicle.
  2.  
  3. Loosen the fuel pump retaining bolts, then lift the fuel pump up and out of the fuel tank.
  4.  
  5. Remove and discard the old fuel pump gasket.
  6.  



Click image to see an enlarged view

Fig. Fig. 1: To remove the electric fuel pump, the fuel tank must be lowered from the underside of the vehicle

To install:
  1. Position the fuel pump, along with a new gasket, in the fuel tank, ensuring that the fuel pump retaining bolt holes are aligned.
  2.  
  3. Install and tighten the fuel pump retaining bolts securely and evenly.
  4.  
  5. Install the fuel tank into the vehicle.
  6.  

TESTING



On Vehicle Inspection

See Figure 2

Remove the fuel tank filler cap.

  1. Have an assistant turn the ignition ON , while you listen at the fuel filler tube opening. The operation of the fuel pump should be heard from the fuel filler tube opening for approximately 3 seconds, then it should stop.
  2.  
  3. Turn the ignition switch OFF .
  4.  
  5. Open the hood to gain access to the fuel return line, connected to the fuel pressure regulator mounted on the throttle body.
  6.  



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Fig. Fig. 2: Sounds from the electric fuel pump should be heard from the fuel tank filler tube opening for approximately 3 seconds after the ignition switch is turnedON

  1. Once again have your assistant turn the ignition ON , while you feel for fuel pressure at the fuel return line near the throttle body. Fuel pressure should be felt at the return line for approximately 3 seconds after the ignition switch is turned ON .
  2.  
  3. If the fuel pump is not heard operating or if no fuel pressure is felt at the return line, there is a problem with the fuel pump or its circuit.
  4.  
  5. Reinstall the fuel tank filler cap.
  6.  

Fuel Pump Circuit Inspection

See Figure 3

For the inspection of the fuel pump circuit, refer to the accompanying diagnostic chart.



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Fig. Fig. 3: Perform this fuel pump circuit test to determine whether the fuel pump circuit is functioning properly or not

FUEL PUMP RELAY CHECK
See Figures 4, 5, 6 and 7

When testing the fuel pump circuit, it may be necessary to inspect the fuel pump relay for defects. Test the relay as follows:

  1. Disconnect the negative battery cable.
  2.  
  3. Remove the fuel pump relay from its mounting bracket after disengaging the wiring harness connector from it.
  4.  



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Fig. Fig. 4: Common fuel pump and main relay electrical circuit schematic



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Fig. Fig. 5: The fuel pump relay is mounted on the heater unit, as shown

  1. Using a Digital Volt-Ohmmeter (DVOM) set on the ohmmeter function, measure the resistance between relay terminals A and B, and between terminals C and D. The resistance between terminals A and B should register infinite resistance (no continuity). The resistance between terminals C and D should be 63-77 ohms at 77°F (25°C). If the resistances were not as indicated, replace the relay.
  2.  
  3. Connect a the negative lead of a 12 volt DC battery to terminal D of the relay, and the positive lead to terminal C of the relay. With the relay energized, measure terminals A and B for continuity. There should now be continuity between terminals A and B. If there is no continuity, replace the relay with a new one.
  4.  
  5. Install the relay, and reattach the wiring harness connector to it.
  6.  



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Fig. Fig. 6: Using a DVOM, measure the resistance between terminals A and B, and terminals C and D on the fuel pump relay



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Fig. Fig. 7: Attach a 12 volt DC battery to terminals C and D, then measure the resistance between terminals A and B again-replace the relay if the resistance is not as specified

Fuel Pump Pressure Output Inspection

See Figures 8 and 9

Prior to performing the following inspection, ensure that the battery voltage is 11 volts or higher. If the battery voltage is too low, the fuel pump pressure will be lower than the specified range, even if the fuel pump and fuel lines are in good condition.

  1. Install a fuel pressure gauge to the fuel delivery manifold, as follows:
    1. Relieve the fuel system pressure.
    2.  
    3. Open the hood.

      Click image to see an enlarged view

      Fig. Fig. 8: Install a fuel pressure gauge (A) onto the end of the fuel delivery pipe (supply manifold) using a fitting (C) and flexible hose (B) designed specifically for this purpose



      Click image to see an enlarged view

      Fig. Fig. 9: The entire fuel delivery system can be checked with a fuel pressure gauge attached to the fuel delivery pipe

    4.  
    5. Using a back-up wrench, loosen the small plug bolt from the end of the fuel delivery pipe (fuel supply manifold).
    6.  
    7. Attach a fuel pressure gauge set (including Suzuki Tools 09912-58441, 09912-5842, and 09919-46010, or their equivalents) to the fuel delivery pipe.
    8.  

  2.  
  3. Turn the ignition switch ON for 3 seconds (without starting the engine), then turn it OFF . Repeat this three or four times, then check the fuel pressure registered on the fuel pressure gauge attached to the fuel delivery manifold. The fuel pressure should be 4.6-42.7 psi (250-10 kPa) for 1.6L engines, or 7.4-44.0 psi (270-20 kPa) for 1.8L engines, and should remain above 28.4 psi (200 kPa) for one minute after the fuel pump stops.

    If the fuel pressure is within the specified range, skip to the next step.
     
    If there was no fuel pressure, jump to Sub-Test 1.
     
    If the fuel pressure was initially within the specified range but dropped below 28.4 psi (200 kPa) within one minute after the fuel pump stopped, skip to Sub-Test 2.
     
    If the fuel pressure was too low, skip to Sub-Test 3.
     
    If the fuel pressure was too high, skip to Sub-Test 4.
     

  4.  
  5. Start the engine and allow it to reach normal operating temperature.
  6.  
  7. Allow the engine to idle and observe the fuel pressure on the gauge. The fuel pressure should be within 29.8-6.0 psi (210-260 kPa) for 1.6L engines, or within 2.3-6.0 psi (220-260 kPa) for 1.8L engines. If the fuel pressure is not as specified, the problem is most likely a clogged vacuum passage for the fuel pressure regulator, or a faulty fuel pressure regulator. If the fuel pressure was within the specified range, the fuel pump and fuel delivery system is functioning normally.
  8.  

SUB-TEST 1
  1. Install a hose pinch clamp on the fuel return hose (attached to the fuel pressure regulator), and pinch the hose closed.
  2.  
  3. Turn the ignition switch ON for 3 seconds (without starting the engine), then turn it OFF . Repeat this three or four times, then check the fuel pressure registered on the fuel pressure gauge attached to the fuel delivery manifold. If there is now the specified amount of fuel pressure, the fuel pressure regulator is faulty. If there is still no fuel pressure, the problem is a shortage of fuel in the fuel tank, or the fuel pump or its circuit is defective.
  4.  

SUB-TEST 2
  1. Inspect the fuel feed line hose, pipe and connections for fuel leaks; fix any leaks found.
  2.  
  3. If no leaks were found, detach the fuel return hose from the fuel pressure regulator. Install a new hose to the pressure regulator, and position the open end of the new hose into a container designed to hold gasoline.
  4.  
  5. Turn the ignition switch ON for 3 seconds (without starting the engine), then turn it OFF . Repeat this three or four times, then check the fuel pressure registered on the fuel pressure gauge attached to the fuel delivery manifold. If, after activating the fuel pump, fuel leaks from the open end of the new regulator hose, the pressure regulator is defective. Otherwise, the problem may lie in one or more of the following:

    Leaking fuel injector
     
    Faulty fuel pump check valve
     
    Leaking fuel pressure regulator diaphragm
     

  6.  

SUB-TEST 3
  1. Install a hose pinch clamp on the fuel return hose (attached to the fuel pressure regulator), and pinch the hose closed.
  2.  
  3. Turn the ignition switch ON for 3 seconds (without starting the engine), then turn it OFF . Repeat this three or four times, then check the fuel pressure registered on the fuel pressure gauge attached to the fuel delivery manifold. If there is now the specified amount of fuel pressure, the fuel pressure regulator is faulty. If the fuel pressure is still too low, the problem may be one or more of the following:

    Clogged fuel filter
     
    Restricted fuel feed hose or pipe
     
    Faulty fuel pump
     
    Fuel leakage from the hose connection in the fuel tank
     

  4.  

SUB-TEST 4
  1. Detach the fuel return hose from the fuel pressure regulator.
  2.  
  3. Install a new hose to the pressure regulator, and position the open end of the new hose into a container designed to hold gasoline.
  4.  
  5. Turn the ignition switch ON for 3 seconds (without starting the engine), then turn it OFF . Repeat this three or four times, then check the fuel pressure registered on the fuel pressure gauge attached to the fuel delivery manifold. If the fuel pressure is now within the specified range, the problem is a restricted fuel return hose or pipe. Otherwise, the pressure regulator is defective.
  6.  

 
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