How do solenoid injectors work on a diesel?

Solenoid injectors in diesel engines operate by using an electromagnetic solenoid to control the injection of fuel into the combustion chamber. When the engine's electronic control unit (ECU) signals the solenoid, it energizes the coil, creating a magnetic field that pulls a plunger down, opening the injector nozzle. This allows pressurized diesel fuel to spray into the combustion chamber at precise timings and quantities, facilitating optimal combustion. Once the signal is cut, a spring returns the plunger to its original position, closing the injector and stopping the fuel flow.