1.15. FUEL SYSTEM

TM 5-3895-373-20 1.15. FUEL SYSTEM. 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 injectors. 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 separator. 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 system. 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. 1-18