Fuel Injector: Description and Operation

CAUTION:
^ Color of Service Parts identification clip may differ from color of Production identification clip. Verify identification using part number and parts catalog.
^ Do not interchange fuel injectors. Improper injector installation can cause severe engine damage.

An electronically controlled/hydraulically actuated fuel injector is used. The rate shape fuel injector incorporates a spill control port that helps balance the fuel delivery, reducing the emissions and engine noise.

When the fuel injector is energized, a poppet valve is opened by an electronic solenoid mounted on the fuel injector. High-pressure oil from the high-pressure oil pump flows into the fuel injector and acts on the amplifier piston, forcing the piston plunger downward. As the plunger moves down, the increased fuel pressure closes the fuel inlet check ball. Rising fuel pressure overcomes spring pressure and opens the nozzle check valve. Fuel is then injected into the combustion chamber through the eight spray orifices in the nozzle tip at pressures as high as 124, 110 kPa (18,000 psi). When the fuel injector is de-energized, high-pressure oil on top of the amplifier piston is vented by the poppet valve through the top portion of the fuel injector back to the oil pan.