Fuel Injector: Description and Operation

Fig. 3 Fuel Injector:

Fig. 4 Fuel Injector Location-Typical:

The fuel injectors are 12 ohm electrical solenoids (Fig. 3). 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. The spraying action atomizes the fuel, adding it to the air entering the combustion chamber. The injectors are positioned in the intake manifold.

The injectors are positioned in the intake manifold with the nozzle ends directly above the intake valve port (Fig. 4).

CIRCUIT OPERATION
Circuit A14 is connected to the BUS bar in the Power Distribution Center (PDC), and connects to battery voltage. The contact side of the Automatic Shut Down (ASD) relay connects circuit A14 and A142. A 20 Amp fuse, in cavity B of the PDC, protects circuits A14 and A142.

The Powertrain Control Module (PCM) controls the ground path for the coil side of the ASD relay on circuit K51. Circuit K51 connects to cavity 67 of the PCM.

Circuit A142 supplies voltage for the fuel injectors. The PCM controls the ground circuit of each injector, as follows:
- Circuit K11 is the ground circuit for Injector #1. Circuit K11 connects to cavity 13 of the PCM.
- Circuit K12 is the ground circuit for Injector #2. Circuit K12 connects to cavity 17 of the PCM.
- Circuit K13 is the ground circuit for Injector #3. Circuit K13 connects to cavity 7 of the PCM.
- Circuit K14 is the ground circuit for Injector #4. Circuit K14 connects to cavity 16 of the PCM.
- Circuit K38 is the ground circuit for Injector #5. Circuit K38 connects to cavity 15 of the PCM.
- Circuit K58 is the ground circuit for Injector #6. Circuit K58 connects to cavity 14 of the PCM.