The electromagnetic valve that stops the fuel feed is assembled in the upper part of the distributor head of the fuel-injection pump. When it is connected, in other words with the diesel engine turned on, the electromagnet keeps the entrance hole to the high-pressure area open.
On taking away contact through the corresponding switch, the coil of the electromagnet no longer has any electrical current. The magnetic field is cancelled and the spring presses the induction against the seat of the valve, meaning that the opening to the high-pressure chamber is closed and the piston distributor stops feeding fuel.
