The fuel tank on Sedan and Coupe models is mounted vertically behind the back of the rear seat. On Wagon models, the fuel tank is installed horizontally under the boot floor. The fuel level sensor is attached to the top of the fuel tank and can be replaced without removing the fuel tank.
The roller-type electric fuel pump is installed under the floor at the rear of the vehicle. The fuel pump is cooled by the fuel flowing through it. The fuel pump has a one-way valve that maintains pressure in the fuel system even after the engine is turned off. The pump also has a bypass valve that limits the maximum pressure in the fuel system.
A pressure accumulator is installed between the fuel pump and the fuel supply hose, which maintains pressure in the fuel system after the engine is turned off. After the pressure accumulator reduces the fluctuations in fuel pressure that occurs in the fuel system during the operation of the fuel injectors.
The cartridge type fuel filter is installed near the pressure accumulator behind the fuel pump.
The fuel quantity measurement is made by the distributor, which mechanically controls the amount of fuel supplied to the fuel injectors based on the deviation of the air flow measurement sensor. The composition of the mixture is adjusted dynamically by the pressure actuator of the electro-hydraulic shock absorber with constant control of the electronic control device (ECU). The ECU is controlled based on signals from sensors located on and around the engine. Constant dynamic adjustment of the fuel mixture improves engine performance, reduces fuel consumption and the amount of harmful substances in the exhaust gases. In addition, a differential pressure valve in the distributor element ensures a constant supply of fuel in all operating modes.
Starting a cold engine is facilitated by a cold start valve and an air assist device. The cold start valve is an electrically controlled fuel injector mounted in the intake manifold that sprays additional fuel into the air entering the engine. Fuel Start Switch (thermal time sensor) controls the time the cold start valve remains open. The air assist device is a valve that allows air to bypass the throttle causing the idle speed to increase. The bimetal plate and heater coil control the amount and time of valve opening. The air assist device only works when starting a cold engine.
On later models, a rotary actuator is installed. This unit replaces the air assist unit and is controlled by the ECU to stabilize idle speed in all operating conditions, including fast idle during warm-up and idle speed control under load.
Models with a catalyst have feedback that, based on the signal from the oxygen sensor, regulates the fuel mixture ratio.
Precautions
The fuel system is under constant pressure, even after the engine has been switched off, so any work on the fuel system must be relieved of pressure.
To prevent the possibility of accidental short circuits in the electrical circuit and damage to the electronic components of the fuel injection system, always remove the ground wire from the battery.
Warning! Gasoline is extremely flammable and explosive, so care must be taken when working on any part of the fuel system.
Attention! Work on the fuel system must be carried out in a well-ventilated area, for which all windows and doors can be opened to create a draft.
Attention! When working on the fuel system, do not use open flames, electric welding, or tools that may generate sparks. Make sure there is a charged fire extinguisher in the immediate vicinity of the workplace.
Attention! Use goggles to protect your eyes from getting fuel in them. If fuel comes into contact with skin, wash the area with plenty of water.
Warning! The container in which the fuel was located contains fuel vapors and is potentially explosive.
Attention! Keep the fuel system clean as dirt entering the fuel system passages can block them and prevent the engine from running properly.