High Pressure Pump

DESCRIPTION

High Pressure Fuel Pump:

WARNING:(Refer to FUEL SYSTEM - WARNING)

The high pressure pump is a fuel regulated radial piston pump with three pistons arranged at an angle of 120° The regulation being carried out by the fuel quantity valve The high pressure pump is driven at about 1.3 times the speed of the camshaft. Specific moving parts inside the pump are graphite coated to assist with the lubrication process during operation The high pressure pump is mounted to the front of the cylinder head and must be replaced as an assembly should a failure occur.

OPERATION

HIGH PRESSURE SIDE

Producing High Pressure:

A. Filling the piston: The piston (6) is moved down as a result of the piston spring (7). The fuel supplied by the fuel delivery pump flows along the ring passage (10), the valve disk and the valve spring (3) into the cylinder. The check ball (4) prevents the fuel from being able to flow back from the high pressure passage (5).

B. Producing high pressure: The piston (6) is moved up by the rising eccentric shaft (9) and the fuel is compressed. The valve (2) disk shuts off the delivery volume to the fuel supply. Once the fuel pressure in the cylinder rises beyond the pressure which exists in the high pressure circuit (5), the check ball (4) opens and the fuel is pumped into the high pressure circuit (5).