Honda - Accord Prelude 1996 2000

Fuel Injector(s)

Print

REMOVAL & INSTALLATION





Click image to see an enlarged view

Fig. You must replace the fuel injector sealing O-ring anytime the injector is removed



Click image to see an enlarged view

Fig. The fuel injector O-ring may be stuck in the intake manifold



Click image to see an enlarged view

Fig. You may need to thoroughly clean the injector tips if there is excessive carbon around the needle and seat



Click image to see an enlarged view

Fig. Exploded view of the fuel rail, injectors and related components-4-cylinder engine shown



Click image to see an enlarged view

Fig. Exploded view of the fuel injector (B), O-rings (C), and seal rings (E)


CAUTION
Observe all applicable safety precautions when working around fuel. Whenever servicing the fuel system, always work in a well-ventilated area. Do not allow fuel spray or vapors to come in contact with a spark or open flame. Keep a dry chemical fire extinguisher near the work area. Always keep fuel in a container specifically designed for fuel storage; also, always properly seal fuel containers to avoid the possibility of fire or explosion.

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


CAUTION
Fuel injection systems remain under pressure, even after the engine has been turned OFF. The fuel system pressure must be relieved before disconnecting any fuel lines. Failure to do so may result in fire and/or personal injury.

  1. Detach the electrical connectors from the fuel rail.
  2.  
  3. Disconnect the vacuum hose and fuel return from the fuel pressure regulator.
  4.  
  5. Loosen and remove the fasteners on the fuel rail, then remove the fuel rail. For more information on fuel rail removal, refer to the procedure in this section.
  6.  
  7. Grasp the fuel injector body and pull up while gently rocking the fuel injector from side to side.
  8.  
  9. Once removed, inspect the fuel injector cap and body for signs of deterioration. Replace as required.
  10.  
  11. Remove and discard the injector O-rings. If an O-ring or end cap is missing, look in the intake manifold for the missing part.
  12.  

To install:

  1. Replace the O-rings and apply a small amount of clean engine oil to them. Install the lubricated O-rings onto each injector.
  2.  
  3. Install the injectors using a slight twisting downward motion.
  4.  
  5. Install the injector retaining clips.
  6.  
  7. Install the fuel injection supply manifold (fuel rail).
  8.  
  9. Connect the negative battery cable.
  10.  
  11. Turn the ignition switch ON for 5 seconds, then turn it OFF and check for fuel leaks.
  12.  
  13. If no fuel leaks are noticed, run the engine at idle for 2 minutes, then turn the engine OFF and recheck for fuel leaks and proper operation.
  14.  

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 mechanic's 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 two earpieces 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; as the solenoid in the injector is 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.

The Honda fuel injectors are triggered by electrical pulses. The injector is either on (open) or off (closed). The amount of fuel the injector provides is determined by the fuel pressure and how long the injector is opened.

When diagnosing a fuel related running problem, it's a good idea to remove the spark plugs and check their color. A rich mixture (too much fuel) is characterized by a black sooty appearing spark plug electrode. A lean mixture (too little fuel) is characterized by a dry, very whitish colored spark plug.

A fuel injector could cause a rich mixture if:



The pressure regulator is defective
 
The system fuel pressure is too high
 
The injector leaks when not being triggered
 
The pressure regulator vacuum line is restricted
 

A fuel injector could cause a lean mixture if:



The pressure regulator is defective
 
The system fuel pressure is too low
 
The injector has fuel flow related blockage
 
The injector sticks or binds when being triggered
 
The internal electrical windings of the injector have failed
 
The injector does not receive an electrical pulse or has a bad ground
 

All Injectors Clicking

If all the injectors are clicking, but you have determined that the fuel system is the cause of your drivability 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 grounding one spark plug wire at a time, or interrupting the voltage signal to an individual ignition coil pack, one unit 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. If the injector leaks fuel without being triggered, replace the leaking injector.

One or More Injectors Are Not Clicking


Click image to see an enlarged view

Fig. Unplug the fuel injector connector



Click image to see an enlarged view

Fig. Probe the two terminals of a fuel injector to check its resistance



Click image to see an enlarged view

Fig. Plug the correct "noid" light directly into the injector harness connector



Click image to see an enlarged view

Fig. If the correct "noid" light flashes while the engine is running, the injector driver circuit of the PCM is working

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 to be tested, 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, test the injector's resistance. The resistance should be between 1.5-2.5 ohms.

If the "noid" light does not flash, the injector driver circuit is faulty. Check the PGM-FI Main Relay operation and the wiring between the PCM. Disconnect the negative battery cable. Unplug the "noid" light from the injector connector and also unplug the PCM. Check the harness between the appropriate pins on the harness side of the PCM 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 PCM is faulty. If available, substitute a known good PCM for diagnostic purposes. If defective, replacement of the PCM will be necessary.

 
label.common.footer.alt.autozoneLogo