1.7L engines
The fuel system consists of a fuel tank installed under the rear of the vehicle, a fuel filter with a water separator, a high pressure fuel pump, fuel injectors and pipelines. Before entering the filter, the fuel is heated by an electric heater, which is attached to the filter housing.
The fuel supply from the fuel filter to the high pressure fuel pump is provided by a booster vane pump located in the high pressure fuel pump. Excess fuel lubricates the high pressure fuel pump and returns to the fuel tank.
The fuel pump is driven by a toothed belt. The speed of rotation of the fuel pump is half the speed of rotation of the crankshaft.
The amount of fuel is controlled by a centrifugal governor, which responds to the position of the fuel control pedal and the speed of the crankshaft. The regulator is connected to a metering valve that increases or decreases the amount of fuel delivered per pump stroke.
The fuel injection timing is changed automatically, depending on the engine speed, by a mechanism that turns the cam plate or ring.
Fuel injectors spray fuel into swirl chambers located in the cylinder head. Fuel injectors must open and close at strictly defined pressures. The fuel injector needle is lubricated by fuel that accumulates near the spring and is directed through the return hose to the fuel pump.
To start a cold engine, glow plugs are used to heat the swirl chambers. The thermostatic capsule on the fuel pump increases the idle speed of a cold engine.
The engine stop solenoid shuts off the fuel supply to the fuel pump rotor when the ignition is turned off.
A turbocharger is installed to increase engine power. At the same time, it raises the air pressure in the intake manifold above atmospheric pressure.
Maintenance of the fuel pump and injectors is very difficult. Therefore, it must be carried out at a service station. For long and trouble-free operation of the fuel pump and injectors, it is necessary to prevent dirt and water from entering the fuel system.
2.0L engines
Warning! There are two versions of the 2L engine: low pressure turbocharged (X20DTL) and high pressure turbocharged (X20DTH).
The fuel system consists of a fuel tank installed under the rear of the vehicle, a fuel filter with a water separator, a high pressure fuel pump, fuel injectors and pipelines. Before entering the filter, the fuel is heated by an electric heater, which is attached to the filter housing.
The fuel supply from the fuel filter to the high pressure fuel pump is provided by a booster vane pump located in the high pressure fuel pump. Excess fuel lubricates the high pressure fuel pump and returns to the fuel tank.
The fuel pump is driven by a toothed belt. The speed of rotation of the fuel pump is half the speed of rotation of the crankshaft.
The fuel pump is controlled by an electronic system. The system consists of an electronic control device (ECU), fuel pump control unit and the following sensors:
- the accelerator pedal control sensor tells the ECU the position of the fuel pedal;
- coolant temperature sensor reports engine temperature to ECU;
- the intake air temperature sensor tells the ECU the temperature of the air passing through the intake port;
- oil temperature sensor reports engine temperature to ECU;
- an airflow meter tells the ECU how much air is flowing; passing through the inlet channel;
- the crankshaft sensor reports the relative position of the crankshaft and its speed;
- the pressure sensor reports the relative pressure in the exhaust manifold;
- the ABS system informs the ECU of the vehicle's relative speed;
- the air conditioning compressor switch tells the ECU to turn on the air conditioning system.
Based on the information received from the sensors, the ECU determines the moment of fuel injection at all temperatures and engine operating modes.
The ECU also controls the exhaust gas reburning system and the engine preheating system.
Fuel injectors spray fuel into swirl chambers located in the cylinder head. Fuel injectors must open and close at strictly defined pressures. The fuel injector needle is lubricated by fuel that accumulates near the spring and is directed through the return hose to the fuel pump.
A throttle valve is installed in the intake manifold to improve the efficiency of the engine at low speeds. Air is supplied to each cylinder through two passages in the intake manifold, one of which contains a valve controlled by the ECU through a solenoid valve and a vacuum diaphragm. At speeds less than 1,500 rpm, the valves are closed, and air enters the cylinders through only one channel. At higher engine speeds, the ECU opens the valves, causing air to enter each cylinder through both intake manifold ports.
A complete check of the injection system can be performed using special electronic diagnostic equipment, which is included in the diagnostic socket of the fuel system. The diagnostic connector is located behind the center console in front of the handbrake lever.
Precautionary measures
The turbocharger operates at extremely high speeds and temperatures. Do not operate the turbocharger with any part or hose removed. Foreign particles falling on the rotating vanes can damage the turbocharger.
Do not rev the engine immediately after starting, especially when the engine is cold. Wait at least a few seconds to ensure proper oil circulation.
Allow the engine to idle for a few minutes before shutting down after running the engine at high RPM.
Use only recommended quality oil to lubricate the engine.
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