In a diesel engine, clean air is sucked into the cylinder and compressed by the piston. As a result of compression, the air temperature rises above the ignition temperature of diesel fuel. In the piston position up to TDC, diesel fuel is injected into the cylinder, which ignites in an air medium whose temperature is about 600°C. Fuel ignition occurs without the use of spark plugs.
In a cold engine, the air temperature required to ignite the fuel is not reached. In this case, additional air heating is required. To do this, a glow plug is installed in the vortex chamber of the diesel engine, which heats the combustion chamber.
The fuel is sucked in by the high pressure fuel pump directly from the fuel tank. In the injection pump, the fuel is compressed to a high pressure (approx. 130 bar) and injected in a certain sequence into the cylinders. At the same time, the injection pump regulator doses the amount of injected fuel in accordance with the position of the gas pedal. Through the injection pump, diesel fuel is injected at the right time into the prechamber of the corresponding cylinder. Due to the shape of the pre-chamber or vortex chamber, the air in the process of compression receives a certain vortex movement, which contributes to optimal mixing of the fuel with air.
Before fuel enters the injection pump, it passes through the fuel filter, where it is separated from contaminants and water. It is necessary to periodically drain the sediment from the filter and change the filter elements.
The injection pump does not require maintenance. The moving parts of the pump are lubricated with diesel oil. The injection pump is driven by a toothed belt from the crankshaft.
Diesel is a self-igniting engine and therefore cannot be stopped like a gasoline engine by interrupting the voltage supply to the ignition system. A magnetic valve is used to stop the diesel. When the diesel engine is turned off, the voltage supply to the solenoid valve is interrupted and the valve shuts off the fuel supply. The solenoid valve receives voltage when the engine is started from the switch and opens the fuel access channel to the injection pump.