Komatsu 114E-3 Series, Shop Manual, Page: 83 / 342

10 Structure, function and maintenance standard SEN00176-02
114E-3 Series
13
Fuel that is metered past the fuel pump actuator will
enter inlet drilling in the high pressure fuel pump
inlet drilling and pass the inlet check valve and fill
the pumping chamber by pressing the pumping
plunger downward.
When the camshaft pushes the pumping plunger
upward, fuel will reach rail pressure and cause the
outlet check valve to lift. Fuel will then enter the out-
let drilling of the fuel pump and exit the high pres-
sure fuel line to the fuel rail.
The fuel filter is a spin-on type.
Fuel flows around the outside of the filter and back
up through the middle. The filtering media is a 10
micron Stratapore design for efficient debris
removal. The filter also strips the water and collects
it at the bottom of the filter to be drained daily.
The lift pump will run for 30 seconds after the key is
switched on to assist with fuel priming. The lift
pump will run during cranking and while the engine
is running until the 30 seconds has lapsed. The lift
pump will shut off anytime the key is switched
“OFF”. The 30 second timer is reset after each key
switch cycle and ECM power down.
Once the engine is started, additional fuel is drawn
through the lift pump head via the gear pump. A
valve in the head opens when the gear pump
requires more flow than the lift pump can provide or
when the lift pump is shut off.