In a cold engine, it is impossible to achieve the ignition temperature of the fuel by compression alone. In this case, the engine is heated (preheated). For this purpose, each swirl chamber of the diesel engine has a glow plug that heats up the combustion chamber. The fuel is sucked directly by the high-pressure fuel pump (HPFP) from the fuel tank. The pump creates the required high pressure (approximately 130 bar) and the fuel is distributed among the cylinders in accordance with the ignition sequence. At the same time, the HPFP regulator doses the fuel supply depending on the degree of activation of the gas pedal. At a certain point in time, diesel fuel is injected through nozzles into the pre-chamber of the corresponding cylinder. Depending on the shape of the pre-chamber, or swirl chamber, the sucked air acquires a vortex motion under the influence of compression, which contributes to optimal mixing of air and injected fuel.
Before entering the injection pump, the fuel passes through the fuel filter. There it is cleaned of impurities and water. Therefore, it is especially important to drain the water from the filter or replace it in accordance with the maintenance schedule.
The high-pressure fuel pump does not require maintenance. All moving parts of the pump are lubricated with diesel fuel. The pump is driven by the crankshaft through a toothed belt, which also drives the camshaft.
Being self-igniting, the diesel engine cannot be switched off by removing the ignition voltage and has a solenoid valve for this purpose. When the ignition switch is switched off, the power is removed from the valve and it closes the fuel supply channel. This ensures that the fuel supply is interrupted before the steering wheel is locked when the ignition key is removed. When the engine is started, voltage is supplied through the ignition switch to the solenoid valve and it opens the fuel supply channel.
(The article is based on data from the website: www.mitsubishiman.ru)