Fuel Injectors
The port fuel injector is a solenoid operated device controlled by the ECM. The ECM energizes solenoid, which in turn opens the valve allowing pressurized fuel to be injected just ahead of intake valve. ECM achieves its predetermined air/fuel ratio by energizing the injector for a specific amount of time.
As the injector is energized a needle valve is opened allowing pressurized fuel to flow past valve and through nozzle. As pressurized fuel flows past nozzle a conical spray pattern is produced. Excess fuel then passes through regulator before returning to tank.
Each injector has 2 "O" rings. The lower "O" ring provides a seal between the injector and intake manifold. The upper "O" ring provides a seal between the injector and fuel rail. Vacuum leakage at the injector intake area will create a lean cylinder or driveability problem.
Each injector has a 2-wire connector. One wire supplies voltage from the fuse(s) in the fuse panel. The second wire connects to ECM, which controls the ground to operate the injector pulse width, or on time. The electric pulses generate a magnetic field in the solenoid winding. As a result, the armature is drawn back and lifts the nozzle valve from its seat approximately .038" (.15 mm). The helical spring closes the nozzle valve.