FUEL INJECTOR
DESCRIPTION
The injectors are positioned in the intake manifold with the nozzle ends directly above the intake valve port.
OPERATION
The fuel injectors are 12 volt electrical solenoids. The injector contains a pintle that closes off an orifice at the nozzle end. When electric current is supplied to the injector, the armature and needle move a short distance against a spring, allowing fuel to flow out the orifice. Because the fuel is under high pressure, a fine spray is developed in the shape of a hollow cone or two streams. The spraying action atomizes the fuel, adding it to the air entering the combustion chamber. Fuel injectors are not interchangeable between engines.
The PCM provides battery voltage to each injector through the ASD relay. Injector operation is controlled by a ground path provided for each injector by the PCM. Injector on-time (pulse-width) is variable, and is determined by the PCM processing all the data previously discussed to obtain the optimum injector pulse width for each operating condition. The pulse width is controlled by the duration of the ground path provided.
REMOVAL
WARNING: Release fuel system pressure before servicing fuel system components. Service vehicles in well ventilated areas and avoid ignition sources. Never smoke while servicing the vehicle. This may result in personal injury or death.
1. Release the fuel pressure, refer to the fuel pressure release procedure.
2. Disconnect the negative battery cable.
3. Disconnect the electrical connectors from the fuel injectors.
4. Fuel line connection at fuel rail.
5. Remove the fuel line from the fuel rail.
6. Remove wire harness from fuel rail mounting studs.
7. Remove the 2 bolts to the fuel rail at the lower manifold.
8. Remove the fuel rail.
9. Remove clip holding fuel injector to fuel rail.
10. Remove fuel injector from fuel rail.
INSTALLATION
1. Apply a light coating of clean engine oil to the upper O-ring.
2. Install injector in cup on fuel rail.
3. Install retaining clip.
4. Apply a light coating of clean engine oil to the O-ring on the nozzle end of each injector.
5. Insert fuel injector nozzles into openings in lower intake manifold. Seat the injectors in place.
6. Tighten fuel rail mounting screws to 27 N·m (20 ft. lbs.).
7. Install wiring harness clips to the fuel rail mounting studs.
8. Attach electrical connectors to fuel injectors, refer to the Fuel Injector Connector in this section for electrical connector installation.
9. Connect fuel supply tube to fuel rail.
10. Connect the negative battery cable.
11. Use the scan tool to pressurize the fuel system. Check for leaks.