Volvo 240/740/760/780/940/960 1990-1998

Fuel Injector(s)

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REMOVAL & INSTALLATION



2.3L 4-Cylinder and 2.8L 6-Cylinder Engines
  1. Relieve the fuel system pressure.
  2.  
  3. Disconnect the negative battery cable.
  4.  
  5. Disconnect the fuel lines, electrical connectors and vacuum hose from the injection manifold and pressure regulator.
  6.  
  7. Unbolt the pressure regulator from the fuel rail bracket.
  8.  
  9. Remove the injector cover plate, if equipped.
  10.  
  11. Remove the fuel injection manifold retaining bolts. Remove the fuel injection manifold and injectors as one unit.
  12.  
  13. Secure the injection manifold in a suitable holding fixture and remove the fuel injectors.
  14.  

To install:
  1. Check the fuel injector O-rings, and replace if necessary.
  2.  
  3. Coat the O-rings with petroleum jelly and install the fuel injectors to the injection manifold.
  4.  
  5. Install the fuel injection manifold and fuel injectors as one unit.
  6.  
  7. Install and tighten the retaining bolts.
  8.  
  9. Install the injector cover plate, if equipped.
  10.  
  11. Connect the pressure regulator to the fuel injection manifold and then attach to the bracket.
  12.  
  13. Connect the vacuum hose, fuel lines and electrical connectors.
  14.  
  15. Connect the negative battery cable.
  16.  
  17. Start the vehicle and check for leaks.
  18.  

2.9L 6-Cylinder Engine
  1. Properly relieve the fuel system pressure.
  2.  
  3. Disconnect the negative battery cable.
  4.  
  5. Remove fuel rail protective cover.
  6.  
  7. Remove the fuel lines from the fuel rail.
  8.  
  9. Label and remove electrical connectors from the injectors.
  10.  
  11. Remove fuel rail retaining bolts.
  12.  
  13. Remove fuel rail assembly by pulling the rail up evenly to ensure the injectors come out of the intake.
  14.  
  15. Remove the injector(s) from the fuel rail.
  16.  

To install:
  1. Lubricate the O-rings on the injectors with petroleum jelly or equivalent and place the injectors into the fuel rail, ensuring that the O-rings are seated.
  2.  
  3. Install the fuel rail assembly. Ensure the O-rings seat properly.
  4.  
  5. Tighten the fuel rail retaining bolts.
  6.  
  7. Install the fuel injector connectors.
  8.  
  9. Install the fuel lines on the fuel rail.
  10.  
  11. Install the protective cover on the fuel rail.
  12.  
  13. Connect the negative battery cable.
  14.  
  15. Start the vehicle and check for leaks.
  16.  
  17. Ensure that the fuel pressure is correct.
  18.  
  19. Shut the engine OFF and install the protective cover on the fuel rail.
  20.  

2.3L and 2.4L 5-Cylinder Engines

See Figures 1, 2, 3 and 4

  1. Remove the throttle pulley cover and shield over the valve on the fuel rail.
  2.  
  3. Properly relieve the fuel system pressure.
  4.  
  5. Disconnect the negative battery cable.
  6.  
  7. Remove or disconnect the following components:

    Upper air charge pipe
     
    Fuel rail cover
     
    Injector connectors
     
    Fuel line clips
     

  8.  
  9. Disconnect the vacuum hose from the pressure regulator.
  10.  
  11. Remove the fuel rail retaining bolts and lift the rail off with the injectors.
  12.  

Handle the fuel injectors with care, to avoid damaging the nozzles or needles. Be sure to retain the rubber dampers from the intake manifold.

  1. Remove the injector(s) to be replaced and soak up any fuel spillage. Make sure that a spacer is in the fuel rail O-ring seat.
  2.  

To install:
  1. Lubricate the O-ring(s) with petroleum jelly, then install the new injector(s) into the rail.
  2.  
  3. Make sure the rubber dampers are installed in the injector ports in the intake manifold.
  4.  
  5. Install the rail into the intake manifold.
  6.  
  7. Install or connect the following:

    New bolts in the fuel rail and tighten to 7.5 ft. lbs. (10 Nm)
     
    Fuel line clips
     
    Injector connector with rubber seal
     
    Fuel rail and throttle pulley covers
     
    Upper air charge pipe
     

  8.  
  9. Connect the negative battery cable.
  10.  
  11. Run the car and check for leaks.
  12.  



Click image to see an enlarged view

Fig. Fig. 1: Remove the injector from the fuel rail and replace the O-ring



Click image to see an enlarged view

Fig. Fig. 2: Make sure the injector spacers are not lost



Click image to see an enlarged view

Fig. Fig. 3: Replace the O-ring on the intake manifold side of the injector as well



Click image to see an enlarged view

Fig. Fig. 4: The rubber dampers for the intake manifold must be installed before the fuel rail is reinstalled

TESTING



The easiest way to test the operation of the fuel injectors is to listen for a clicking sound coming from the injectors while the engine is running. This is accomplished using a mechanics stethoscope, or a long screwdriver. Place the end of the stethoscope or the screwdriver (tip end, not handle) onto the body of the injector. Place the ear pieces of the stethoscope in your ears, or if using a screwdriver, place your ear on top of the handle. An audible clicking noise should be heard; this is the solenoid operating. If the injector makes this noise, the injector driver circuit and computer are operating as designed. Continue testing all the injectors this way.


CAUTION
Be extremely careful while working on an operating engine, make sure you have no dangling jewelry, extremely loose clothes, power tool cords or other items that might get caught in a moving part of the engine.

All Injectors Clicking

If all the injectors are clicking, but you have determined that the fuel system is the cause of your driveability problem, continue diagnostics. Make sure that you have checked fuel pump pressure as outlined earlier in this section. An easy way to determine a weak or unproductive cylinder is a cylinder drop test. This is accomplished by removing one spark plug wire at a time, and seeing which cylinder causes the least difference in the idle. The one that causes the least change is the weak cylinder.

If the injectors were all clicking and the ignition system is functioning properly, remove the injector of the suspect cylinder and bench test it. This is accomplished by checking for a spray pattern from the injector itself. Install a fuel supply line to the injector (or rail if the injector is left attached to the rail) and momentarily apply 12 volts DC and a ground to the injector itself; a visible fuel spray should appear. If no spray is achieved, replace the injector and check the running condition of the engine.

One or More Injectors Are Not Clicking

If one or more injectors are found to be not operating, testing the injector driver circuit and computer can be accomplished using a noid light. First, with the engine not running and the ignition key in the OFF position, remove the connector from the injector you plan to test, then plug the noid light tool into the injector connector. Start the engine and the noid light should flash, signaling that the injector driver circuit is working. If the noid light flashes, but the injector does not click when plugged in, replace the injector and retest.

If the noid light does not flash, the injector driver circuit is faulty. Disconnect the negative battery cable. Unplug the noid light from the injector connector and also unplug the ECM. Check the harness between the appropriate pins on the harness side of the ECM connector and the injector connector. Resistance should be less than 5.0 ohms; if not, repair the circuit. If resistance is within specifications, the injector driver inside the ECM is faulty and replacement of the ECM will be necessary.

 
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