REMOVAL & INSTALLATION
- Disconnect the negative battery cable.
- Relieve the fuel system pressure.
- Detach the electrical connectors from the fuel rail.
- Disconnect the vacuum hose and fuel return from the fuel pressure regulator.
- Loosen and remove the fasteners on the fuel rail, then remove the fuel rail.
- Grasp the fuel injector body and pull up while gently rocking the fuel injector from side to side.
- Once removed, inspect the fuel injector cap and body for signs of deterioration. Replace as required.
- 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.
- Replace the O-rings and apply a small amount of clean engine oil to them. Install the lubricated O-rings onto each injector.
- Install the injectors using a slight twisting downward motion.
- Install the injector retaining clips.
- Install the fuel injection supply manifold (fuel rail).
- Connect the negative battery cable.
- Turn the ignition switch ON for 5 seconds, then turn it OFF and check for fuel leaks.
- 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.
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.
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:
A fuel injector could cause a lean mixture if:
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. 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
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.