Toyota Previa 1991-1997 Repair Information

Fuel Injectors

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REMOVAL & INSTALLATION



See Figures 1 through 21

  1. Disconnect the negative battery cable.
  2.  
  3. Relieve the fuel pressure.
  4.  



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Fig. Fig. 1: Exploded view of the fuel injectors and related components necessary for removal


CAUTION
Fuel injection systems remain under pressure after the engine has been turned OFF. Properly relieve fuel pressure before disconnecting any fuel lines. Failure to do so may result in fire or personal injury.

  1. Remove the right engine service hole cover.
  2.  
  3. Disconnect the PCV hose.
  4.  



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Fig. Fig. 2: Remove the PCV hose and valve

  1. Disconnect the vacuum hose and fuel return hose from the pressure regulator.
  2.  
  3. To disconnect the engine wiring harness, separate the harness from the intake manifold and delivery pipe. Disconnect the four injector harnesses. Make sure you label the wiring
  4.  



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Fig. Fig. 3: Remove these four bolts for the engine wiring harness, along with two on the left side not shown



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Fig. Fig. 4: Remove the injector harness clips



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Fig. Fig. 5: Remove the harness from the injectors

  1. Disconnect the fuel inlet pipe by removing the union bolt and two gaskets.
  2.  



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Fig. Fig. 6: Place paper or cloth under the hose fittting before loosening



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Fig. Fig. 7: Remove the union bolt with gaskets to separate the fuel inlet pipe



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Fig. Fig. 8: The union bolt (1), washers (2) and fuel pipe (3)

  1. Unbolt and remove the delivery pipe, injectors and two spacers.
  2.  



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Fig. Fig. 9: Remove these two bolts to extract the delivery pipe ...



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Fig. Fig. 10: ... make sure the spacers are not lost during removal



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Fig. Fig. 11: The whole rail with injectors will come off the cylinder head

  1. Remove the four insulators from the delivery pipe.
  2.  
  3. Remove the injector covers.
  4.  



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Fig. Fig. 12: Remove these four bolts to pull off the injector covers



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Fig. Fig. 13: The covers are simply a small metal plate



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Fig. Fig. 14: Apply gasoline between the delivery pipe and injectors before removal

  1. Remove the delivery pipe with injectors.
  2.  
  3. Remove the four gaskets at the end of the delivery pipe.
  4.  



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Fig. Fig. 15: Remove the four grommets on each end of the delivery pipe where an injector is

  1. Apply gasoline between the delivery pipe and injectors.
  2.  
  3. Place SST 09268-74010 or equivalent pin on the injector nozzle and push down on the delivery pipe to press out the injector.
  4.  



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Fig. Fig. 16: Press the injector out of the delivery pipe

  1. Remove the four injectors from the delivery pipe.
  2.  
  3. Remove the insulator and two O-rings from each injector.
  4.  

To install:
  1. Apply a light coat of gasoline to two new O-rings.
  2.  
  3. Install the two O-rings and new insulator to each injector.
  4.  



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Fig. Fig. 17: Apply a light coat of gasoline to O-rings and install them to the injector

  1. By hand, push in the injector so that the injector connectors are in position.
  2.  
  3. Install the four insulators to the delivery pipe.
  4.  
  5. Install the two spacers, delivery pipe and two bolts. Tighten the bolts to 14 ft. lbs. (20 Nm).
  6.  
  7. Connect the fuel pipe with the gaskets and the union bolt and tighten the bolts to 20 ft. lbs. (29 Nm).
  8.  
  9. Attach the four injector connectors.
  10.  
  11. Secure the engine wire to the intake manifold and delivery pipe.
  12.  
  13. Connect the vacuum hose and fuel return hose to the pressure regulator.
  14.  
  15. Install the PCV hose.
  16.  
  17. Install the right hand engine service hole cover.
  18.  
  19. Connect the negative battery cable.
  20.  
  21. Start the engine and check for leaks.
  22.  

TESTING



See Figures 18, 19, 20 and 21


CAUTION
Keep clear of sparks or flame during testing.

The simplest way to test the injectors is simply to listen to them with the engine running. Use either a stethoscope-type tool or the blade of a long screw driver to touch each injector while the engine is idling. You should hear a distinct clicking as each injector opens and closes.



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Fig. Fig. 18: Fuel injector testers can be purchased or sometimes rented



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Fig. Fig. 19: Place the sound scope on the injector to inspect for normal operation

If you have no sound scope, you can check the injector transmission operation with your finger. If no sound or unusual sound is heard, check the wiring connector, injector or injection signal form the ECM.



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Fig. Fig. 20: Place your finger over the injector if a scope is not available

Additionally, the resistance of the injector can be easily checked. Disconnect the negative battery cable and remove the electrical connector from the injector to be tested. Use an ohmmeter to check the resistance across the terminals of the injector. Correct resistance is between 13.4-14.2 ohms at 68°F (20°C); slight variations are acceptable due to temperature conditions.



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Fig. Fig. 21: Testing the fuel injector with an ohmmeter

Never attempt to check a removed injector by hooking it directly to the battery. The injector runs on a much smaller voltage and the 12 volts from the battery will destroy it internally.

 
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