Engine cut-off solenoid

ENGINE CUT-OFF SOLENOID

Checking operation of engine cut-off solenoid (on fuel injection pump)

– Switch the ignition on (MAR position) in order to energize the engine cut-off solenoid on the fuel injection pump.

The noise of the solenoid being triggered should be heard from the engine compartment. If not, check the operation of the solenoid and if it is satisfactory, check for a break in the connecting cable between the ignition switch and the engine cut-off solenoid (see wiring diagram).

1. Engine cut-off solenoid

DEVICE FOR AUTOMATIC ADVANCE UNDER COLD CONDITIONS (K.S.B.)

Components

The electrical components of this device are:

– A thermal switch (1) located on the thermostat for the engine coolant;

– a wax thermal bulb (2).

Operation

– The purpose of this device is to advance the point of fuel injection in order to ensure regular operation of the engine under cold conditions, by acting on the injection pump’s internal advance mechanism by means of the transfer pressure.

This is cancelled when the engine coolant reaches a temperature of about 60 °C. At this temperature, the wax bulb (2), which is supplied by the thermal switch (1), begins to warm up. The wax it contains expands, pushing out a rod which in turn pushes a ball valve.

This valve opens, discharging the fuel injection pump’s transfer pressure, so restoring the normal operating advance values (see “Fuel system” section).

1. Thermal switch
2. Wax bulb