FUEL INJECTOR OPERATION
1. Screw. 2. Rocker arm. 3. Clamp. 4. Control rod. 5. Rack. 6. Plunger. 7. Litter assembly. 8. Camshaft.
seat to give line contact.
The valve opens at
A flat check valve is used above the needle
approximately 20 000 to 23 300 kPa (2800 to 3400 psi)
valve to keep the high pressure combustion gases out of
and closes at approximately 10 300 kPa ( 1500 psi). The
the injector. If the needle valve is held open by small
fuel flows from the chamber inside the barrel through
foreign particles for a moment between injection cycles,
drilled passages and grooves in the spring cage, and
combustion gases can come into the injector and cause
then through passages around the guide section of the
damage. The injector operates with the flat check valve
valve to the valve chamber. Here the fuel pressure lifts
until the foreign particle has washed on through and
the needle valve off its seat, and the fuel now flows
normal operation takes place.
through the spray tip and out the orifices into the