With a very cold engine, the ignition temperature may not be reached when the air is compressed. In this case, the engine must be warmed up. To do this, each swirl chamber has a glow plug that heats the combustion chamber. At the same time, in order for a cold engine to start better, the moment of injection of the high-pressure fuel pump (high pressure fuel pump) is shifted in the advance direction, so that the fuel is injected into the hot air earlier. As soon as the engine reaches its operating temperature, the injection timing is automatically reversed. The injection timing is controlled by the DDE control unit (DDE - Digital Diesel Electronics), which also controls the amount of fuel injected and the boost pressure from the turbocharger.
Fuel from the tank is supplied to the engine with the help of a fuel priming pump and high pressure fuel pump located in the fuel tank. The injection pump creates the necessary high fuel pressure necessary for its injection into the engine (about 160 bar), and the fuel is distributed to the cylinders in accordance with the order of their operation. The amount of fuel injected is determined by the DDE control unit depending on the position of the accelerator pedal, which is determined by a potentiometer. Through injectors, diesel fuel is injected at the right time into the prechamber of the corresponding cylinder. Due to the shape of the prechamber or vortex chamber, the incoming air flow acquires a vortex-like motion, i.e. mixes optimally with the injected fuel.
Before the fuel enters the injection pump, it passes through the fuel filter, which cleans it of dirt and water. In this regard, it is very important, in accordance with the maintenance plan, to remove water from the filter and replace the injection pump is a maintenance-free unit. All moving parts are lubricated with diesel fuel. The injection pump is driven from the crankshaft by a chain.
Since the diesel engine runs on self-ignition and cannot be stopped by disconnecting the voltage from the ignition system, there is a solenoid valve on the injection pump. When the ignition is turned off, the supply voltage to this valve is turned off, and the valve closes the fuel supply channel. The engine then stops. When the engine is started, the valve is energized by the ignition switch and the valve opens the fuel passage.
The DDE control unit detects the occurrence of malfunctions in the injection system and stores their codes in memory. Workshop with diagnostic tool (motor tester), which is connected to the control unit, read the fault codes and then erase them.