Fuel Delivery and Air Induction: Description and Operation

Through the action of a governor and timer, the diesel fuel system feeds highly pressurized fuel in the required amount, at the correct time to the combustion chamber depending upon engine operating conditions.

Fig. 14 Fuel delivery system:

FUEL DELIVERY SYSTEM

Fuel is pumped from the fuel tank, Fig. 14, by a feed pump located on the injection pump assembly to the fuel filter. The fuel filter maintains a constant volume of fuel and returns excess fuel to the tank through an overflow valve on top of the filter. Fuel passes through the filter into the injection pump plunger which pressurizes a metered amount of fuel into the delivery valve. Fuel is injected into the combustion chamber through the nozzle under constant injection starting pressure.

CONTROL SYSTEM

The diesel pump control system is provided to control excess fuel when starting, cut fuel when stopping the engine, and control engine speed under normal driving conditions. The governor, which is coupled to the injection pump maintains the fixed engine speed when the fuel injection rack is held at a fixed position, maintains idle speed, and provides maximum engine speed control. Fuel enrichment for starting and fuel shut off when shutting off the engine are controlled by diesel pump controller assembly, D.P.C. module, and ignition switch.