1.15.1. Engine Combustion Fuel System.
The engine combustion fuel system consists of a
fuel tank, fuel/water separator, fuel lift pump, fuel filter,
two test transmitters, fuel injection pump, and engine fuel
The fuel tank is a 28 gal (106 Q) fuel storage source for
the paving machine. The fuel tank fill contains a strainer
for filtering out large particles. An electrical fuel level
transmitter controls the fuel gauge on the operator
control panel. The fuel tank outputs to a fuel/water
A diaphragm-type fuel lift pump draws fuel from the fuel
tank through a fuel/water separator, forcing the fuel on to
the test transmitters and the fuel filter. The fuel pump is
driven by an eccentric on the engine cam. A lever on the
fuel pump can be used to manually feed fuel through the
The fuel pump output is sent to the first transmitter which
measures fuel pressure for use by the STE/ICER Test
Set, Test No. 24. The second transmitter measures fuel
pressure into the fuel filter and compares it with the fuel
pressure out of the fuel filter for STE/ICER Test No. 26.
The fuel filter has two inputs that remove impurities from
the fuel supply through a filter. One input is from the fuel
lift pump and the second input is from the overflow of the
injectors on the engine. Two outputs from the fuel filter
feed the injection pump. A third output is a return to the
fuel tank for excess fuel.
Fuel is forced from the fuel filter to a fuel injection pump.
This pump uses both a high pressure and a low pressure
input. The pump is driven by engine timing gears to
provide fuel to each cylinder injector. Excess fuel
supplied to the injectors is returned to the fuel filter.