Toyota Pick-ups/Land Cruiser/4Runner 1989-1996

Fuel Injectors

Print

OPERATION



There is one fuel injector for each cylinder and a cold start injector which provides additional fuel during start-up. The injectors spray fuel into the intake port, in front of the intake valve. When the injector is energized, the coil pulls the plunger up, opening the needle valve and allowing the pressurized fuel to pass through the injector. Injectors operation is controlled by the EFI computer. The injectors operate at low pressure and are open for only a fraction of a second at a time.

REMOVAL & INSTALLATION



22R-E, 3VZ-E and 3F-E Engines
  1. Disconnect the negative battery cable.
  2.  
  3. Safely discharge the fuel pressure in the system. Place a suitable container under the intake manifold to catch any dripping fuel.
  4.  
  5. On 3VZ-E and 22R-E engines, drain the coolant.
  6.  
  7. Disconnect the accelerator and throttle cable.
  8.  
  9. Remove the air intake chamber. Removal of the throttle body is required on 22R-E engine. On the 3F-E engine, make particularly certain all vacuum hoses and wires are labeled; they are numerous.
  10.  
  11. Tag and disconnect all hoses and wires which interfere with injector removal.
  12.  
  13. On 3VZ-E and 3F-E engines, the main engine wiring harness must be moved out of the way. This will require unplugging various connectors at components on the engine until the harness can be repositioned. Label everything before disconnecting it.
  14.  
  15. Unplug the wiring connectors from the tops of the fuel injectors and remove the two plastic clamps that hold the wiring harness to the fuel delivery pipe.
  16.  
  17. For the 22R-E and 3F-E engines, disconnect the fuel line to the fuel delivery rail. Carefully remove the fuel rail (with the injectors attached) from the engine. Do not allow the injectors to fall out during removal.
  18.  
  19. For the 3VZ-E engine, disconnect the vacuum hose from the Bimetal Vacuum Switching Valve (BVSV). Remove the four union bolts and Nos. 2 and 3 fuel pipes. Pull the injectors from the delivery pipes.
  20.  

To install:
  1. Insert new insulators into the injector holes on the intake manifold.
  2.  
  3. Install the grommet and a new O-ring to the delivery pipe end of each injector.
  4.  
  5. Apply a thin coat of gasoline to the O-ring on each injector and then press them into the delivery pipe. Make absolutely certain the injector is squarely and firmly mounted in the pipe; it must not be crooked.
  6.  
  7. Install the injectors together with the delivery pipe in the intake manifold. Tighten the mounting bolts to 11-15 ft. lbs. (15-20 Nm). Once installed, make sure the injectors turn freely in their mounts. If one doesn't turn, remove the injector and check the O-ring.
  8.  
  9. Clip the wiring harness into the delivery pipe and then plug the wiring connectors to the top of each injector.
  10.  
  11. Reconnect all hoses and wires.
  12.  
  13. Install the throttle body and air intake chamber.
  14.  
  15. If the throttle body was removed, refill the engine coolant. Connect the battery cable.
  16.  
  17. Start the engine and check for any fuel leaks.
  18.  

2RZ-FE and 3RZ-FE Engines
  1. Disconnect the negative battery cable.
  2.  
  3. Safely discharge the fuel pressure in the system. Place a suitable container under the intake manifold to catch any dripping fuel.
  4.  
  5. Remove the throttle body.
  6.  
  7. Unplug the four injector connectors, crankshaft position sensor and knock sensor connectors.
  8.  
  9. Disconnect the Data Link Connector (DLC1) and wire clamp from the brackets.
  10.  
  11. Remove the delivery pipe and injectors from the engine.
  12.  
  13. Disconnect the vacuum sensing hose from the fuel pressure regulator.
  14.  
  15. Place a suitable container and a shop rag under and around the delivery pipe to keep the fuel from spurting out. Then slowly loosen the union bolt and 2 gaskets, disconnect the fuel inlet pipe from the delivery pipe.
  16.  
  17. Remove the 2 bolts and the delivery pipe together with the 4 injectors.
  18.  

Be careful not to drop the injectors when you are removing the injector pipe.

  1. Remove the 4 insulators from the spacers.
  2.  
  3. Pull out the injectors from the delivery pipe.
  4.  
  5. Remove the O-ring and grommet from each injector.
  6.  

To install:
  1. Install a new grommet to the injector.
  2.  
  3. Apply a light coat of gasoline to the new O-ring, then install it to the injector.
  4.  
  5. While turning the injector to the left and right, install it to the delivery pipe. Install the injectors.
  6.  
  7. Position the injector connector upward.
  8.  
  9. Place the new insulators in position on the spacers. Place the injectors together with the delivery pipe into position on the cylinder head.
  10.  
  11. Temporarily install the bolts holding the delivery pipe to the head.
  12.  
  13. Check the the injectors rotate smoothly. If they do not, recheck the O-ring installation. Replace the O-rings if necessary.
  14.  
  15. Position the injector upward, then tighten the bolts holding the delivery pipe to the head to 15 ft. lbs. (21 Nm).
  16.  
  17. Connect the fuel inlet pipe to the delivery pipe with new gaskets and the union bolt. Tighten to 22 ft. lbs. (29 Nm).
  18.  
  19. Attach the fuel return hose to the pressure regulator.
  20.  
  21. Attach the vacuum sensing hose to the pressure regulator.
  22.  
  23. Connect the engine harness.
  24.  
  25. Install the throttle body.
  26.  
  27. Fill the cooling system, attach the negative battery cable.
  28.  

TESTING



See Figures 1, 2 and 3

Proper testing of the fuel injectors requires specific equipment not usually available outside a dealership. It is recommended that any checking or testing of the injectors, other than that included in this section, be left to a properly equipped service facility.

Injector operation can be checked with the injectors installed in the engine. A sound scope, which is a stethoscope-like device available from most auto tool and parts jobbers, is recommended, although a piece of good rubber hose will suffice.



Click image to see an enlarged view

Fig. Fig. 1: A sound scope is usually used to inspect injector operation



Click image to see an enlarged view

Fig. Fig. 2: If a sound scope is not available, check the operation with your finger

With the engine running or cranking, check each injector for normal operating noise (a buzzing or humming), which changes in proportion to engine rpm. If a sound scope is not available to you, check injector operation by touching each injector with your finger. It should be buzzing. If no sound or an unusual sound is heard, check the wiring connector, or have the injector checked professionally.

With the engine OFF , measure injector resistance by unplugging the wiring connector from the injector, and connecting an ohmmeter across the injector terminals. Check the continuity at both terminals; resistance should be: cold 12-16 ohms. Resistance will vary with injector temperature.



Click image to see an enlarged view

Fig. Fig. 3: An ohmmeter is used to check injector resistance

 
label.common.footer.alt.autozoneLogo