FUEL SYSTEM CONTINUED
Pre-injection metering starts with the injector plunger and the injector tappet at the top of the fuel injection stroke.
When the plunger cavity is full of fuel, the poppet valve is in the open position and the nozzle check is in the open
position. Fuel leaves the plunger cavity when the rocker arm pushes down on the tappet and the plunger. Fuel flow
that is blocked by the closed nozzle check valve flows past the open poppet valve to the fuel supply passage in the
cylinder head. If the solenoid is energized, the poppet valve remains open and the fuel from the plunger cavity
continues flowing into the fuel supply passage.
Figure 8. Pre-Injection.