Fuel Shut-off Solenoid: Description and Operation

HI PRESSURE FUEL SHUTOFF SOL
The high pressure fuel injection pump has a integrated shut off valve for one of the high pressure pump elements. The ECM monitors the fuel temperature and will switch off the element if the fuel temperature reaches above 287° F (120° C) with the engine speed above 2200 rpm. The shut off valve is not serviced separately.

The high pressure injection pump element shut off valve interrupts the fuel high pressure delivery of one of the injection pump elements in the part load range. This will reduce the power required for driving the high pressure pump so as to reduce the fuel temperature. The pump element is switched off if the fuel temperature is excessively high forcing it to return again to the fuel feed to cool. The element shut off limits the increasing pressure of the injection pump to ensure that the critical fuel temperature for the system is not exceeded.