Nissan Pick-ups and Pathfinder 1989-1995

Fuel Injector

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REMOVAL & INSTALLATION



See Figures 1 through 13

  1. Release the fuel system pressure, as described previously in this section.
  2.  
  3. Disconnect the negative battery cable.
  4.  
  5. Remove the throttle body assembly, as previously outlined.
  6.  
  7. Remove the rubber seal and the injector harness grommet from the top of the throttle body. Remove the injector cover.
  8.  



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Fig. Fig. 1: Tap the bottom of the fuel injector to remove the assembly



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Fig. Fig. 2: Use a hollow bar to avoid damage to the injector assembly



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Fig. Fig. 3: Check the fuel injector for deformities



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Fig. Fig. 4: Tilt the lock tongue with a small screwdriver in order to separate the terminal



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Fig. Fig. 5: Detaching the harness connector

  1. Use a hollow bar with an inside diameter of not less than 0.217 in. (5.5mm) and, with the throttle valve kept fully open, tap the bottom of the fuel injector with the hollow bar and plastic hammer.
  2.  

The Z24i engine uses one injector, while the VG30i engine uses two injectors.

  1. Detach the injector harness from the harness connector using the following procedure:
    1. Remove the terminal retainer.
    2.  
    3. Using a small screwdriver, tilt the lock tongue and, at the same time, push out the terminal.
    4.  

  2.  

To install:
  1. Route the new injector's harness through a new grommet and into the harness tube.
  2.  



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Fig. Fig. 6: Common injector assembly



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Fig. Fig. 7: Press the injectors into the throttle body



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Fig. Fig. 8: Apply silicone to the harness grommet



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Fig. Fig. 9: Always replace the O-rings before installing the fuel injectors



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Fig. Fig. 10: Tighten the injector cover screws in a crisscross pattern



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Fig. Fig. 11: Installing the throttle body seal

Every time a harness grommet is removed, it should be replaced with a new one. When assembling the connector, pay attention to the harness color and position; otherwise, injector damage could occur.

  1. Replace all injector O-rings with new ones coated with some silicone oil.
  2.  
  3. Push the injector(s) into the injector body by hand, until the O-rings are fully seated. Invert the injection body and insure that the injector tips are properly seated.
  4.  
  5. Apply some silicone bond to the injector harness grommet.
  6.  

Airtight sealing is essential to ensure stable and proper idling condition.

  1. Use locking sealer on the screw threads and reinstall the injector cover. Tighten the screws to 2.5 ft. lbs. (3 Nm) in a crisscross pattern to ensure proper seating of the injector and cover.
  2.  
  3. Apply some silicone bond to the bottom of the rubber seal and attach the seal to the top face of the throttle body.
  4.  



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Fig. Fig. 12: Checking the throttle body for leaks



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Fig. Fig. 13: Exploded view of the throttle body assembly-VG30i engine (Z24i engine similar)

Do not reinstall the air cleaner until the silicone bond has hardened.

  1. Install the injection unit to the intake manifold and tighten the bolts evenly to 9-13 ft. lbs. (12-18 Nm). Install/connect all components which were disturbed during throttle body removal.
  2.  
  3. Connect the negative battery cable and make all necessary fuel system adjustments.
  4.  

ADJUSTMENTS



Fast Idle Speed

See Figures 14 and 15

  1. Start the engine and run it until it reaches normal operating temperature.
  2.  
  3. Make sure that the aligning mark stamped on the fast idle cam meets the center of the roller installed on the cam follow lever. If not, correct the location of the fast idle cam by turning the adjusting screw ( S1 ).
  4.  



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Fig. Fig. 14: Fast idle adjustment



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Fig. Fig. 15: Measure clearance G with a thickness gauge

If it is not adjustable, replace the thermo element.

  1. Measure the clearance G between the roller and the fast idle cam. The clearance should be 0.020-0.118 in. (0.51-3.00mm) for the VG30i engine or 0.028-0.118 in. (0.71-2.99mm) for the Z24i engine.
  2.  
  3. If not correct, adjust clearance G by turning the adjusting screw ( S2 ). Make sure the engine is warmed up sufficiently and adjust to 0.031-0.047 in. (0.787-1.194mm) for the VG30i engine or 0.047-0.063 in. (1.194-1.600mm) for the Z24i engine.
  4.  

FICD Solenoid

See Figures 16 and 17

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Fig. Fig. 16: Fast Idle Control Device (FICD) adjustment



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Fig. Fig. 17: Replacing the Fast Idle Control Device (FICD)

  1. With the engine at normal operating temperature, check the idle speed and adjust, as necessary. For details and specifications, please refer to Engine Performance and Tune-up of this repair guide.
  2.  
  3. Turn the air conditioner switch ON . With the A/C is on, the idle speed should be:

    VG30i engine: 750-850 rpm with the manual transmission in N, or 650-700 rpm with the automatic transmission in D.
     
    Z24i engine: 750-850 rpm with the manual transmission in N, or 600-700 rpm with the automatic transmission in D.
     

  4.  
  5. If out of specification, adjust the idle speed by turning the adjusting screw.
  6.  

Dashpot

See Figure 18

  1. Run the engine to normal operating temperature.
  2.  



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Fig. Fig. 18: Dashpot adjustment

  1. Turn the throttle valve by hand, and read the engine speed when the dashpot just touches the adjusting screw.
  2.  
  3. The dashpot touch speed is:

    VG30i engine: 1600-1800 rpm on manual transmission models, or 2000-2200 rpm on automatic transmission models.
     
    Z24i engine: 2700-3300 rpm on all applications.
     

  4.  
  5. If out of specifications, adjust the VG30i engine by turning the dashpot adjusting screw. On the Z24i engine adjust (with the throttle valve closed) by turning the adjusting screw until it touches the dashpot. Then turn the adjusting screw an additional 4 turns.
  6.  

 
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