Fuel Injectors Description

Fig. 4 Fuel Injector:

Fig. 5 Fuel Injector Location-Typical:

OPERATION
The fuel injectors are 12 ohm electrical solenoids (Fig. 4). 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 with the nozzle ends directly above the intake valve port (Fig. 5).

CIRCUIT OPERATION
Circuit A14 is a 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 circuit A142. A 20 Amp fuse in the PDC protects circuits A14 and A142.

Circuit A14 also supplies voltage to the coil side of the ASD relay. The Powertrain Control Module (PCM) controls the ground circuit for the coil side of the ASD relay on circuit K51. Circuit K51 connects to cavity 67 of the PCM connector.

Circuit A142 supplies voltage for the fuel injectors. The PCM controls the ground circuit of each injector.
- 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.