Fuel is drawn from the tank by a vane pump built into the injection pump's delivery head. Before reaching the pump, the fuel passes through a filter that traps dirt and water. The injection pump is driven by the timing belt and its speed is half the crankshaft rotation speed. The high pressure required to inject fuel into the swirl chambers is achieved by using two opposing pistons that are pressed against each other by rollers rotating in a cam washer. Fuel passes through a central rotor, which has one outlet channel that aligns with the holes leading to the fuel pipes of the injectors. Fuel metering is carried out using a centrifugal regulator, which responds to the position of the gas pedal and engine speed. The regulator is connected to a metering valve that moves the rotor sleeve to increase or decrease the amount of fuel supplied to the high pressure chambers. Injection synchronization (ignition timing) are changed using a cam washer to ensure compliance with the prevailing engine speed.
The engines in question have 4 precision injectors that inject a uniform stream of fuel into swirl chambers located in the cylinder head. The injectors are calibrated to open and close at specific pressures, ensuring efficient and even combustion of the fuel. The needle of each injector is lubricated with fuel, which accumulates in a special chamber and is directed to the return hose of the fuel injection pump through bypass tubes.
Depending on the model, a Bosch or Lucas CAV/Roto-Diesel fuel system may be installed. The latter components are marked "Lucas CAV" or "Roto-Diesel" (depending on the date and place of manufacture). Pre-heater plugs or glow plugs are located in swirl chambers to facilitate starting a cold engine. In addition, the cooling system is equipped with a thermostatic sensor that activates the fast idle lever in order to increase engine speed and provide additional fuel to it during a cold start.
The shut-off solenoid cuts off the fuel supply to the injection pump rotor when the ignition is turned off. In addition, a manual shut-off lever is provided for emergency situations.
Maintenance of the fuel injection pump and injectors is limited to minor operations. All work, except those specified in this chapter, must be performed by a specialist.