HIGH-PRESSURE FUEL PUMP The high-pressure fuel pump is mounted on the front side of the gear case and is driven by the A-bank idler gear. The high-pressure pump utilizes a break away driven gear, which disengages itself in the event of a pump failure to prevent engine gear train damage. LOW-PRESSURE FUEL SUPPLY LINE HIGH-PRESSURE PUMPING UNITS HIGH-PRESSURE RAIL SUPPLY LINE, B-BANK HIGH-PRESSURE PUMP CONTROL SOLENOID HIGH-PRESSURE PUMP HIGH-PRESSURE PUMP BODY FUEL RETURN LINE TO JUNCTION BLOCK HIGH-PRESSURE RAIL SUPPLY LINE, A-BANK Fig. 15 High-pressure Fuel Pump Installation. The high-pressure pump receives filtered low-pressure fuel from the fuel delivery pump at the control solenoid.
The high-pressure pump control solenoid meters the amount of fuel entry to the high-pressure pump body and pumping units. The control solenoid is 24 volt operated to close against spring pressure in the open direction. (See Page 23). Part of the fuel received by the high-pressure pump passes to the pump crankcase where it provides lubrication and cooling to the pump camshaft bearings and ceramic rings. The lubrication and cooling fuel exits the high- pressure pump body by a fuel return line to the fuel junction block (See Fig. 15). Page 17