The electronic system of injection of fuel (EFI — Electronic Fuel Injection) consists of three subsystems:
– systems of supply of air in engine cylinders;
– systems of electronic control;
– fuel system.
Basic element of system is the control unit the engine (PCM) which on the basis of information from many sensors operates fuel nozzles, changing length of an impulse, i.e. an interval of time when nozzles are open. It provides preparation of the toplivovozdushny mix corresponding to demanded operational power setting.
The system of supply of air in cylinders of the engine consists of the air filter, branch pipes, throttle knot, the monitoring system of a mode of idling and an inlet collector. On models till 2001 of release the inlet collector and the distributive chamber of submitted air represent one knot.
On models since 2001 of release specially developed inlet collector with capacity adjustment is established.
The throttle knot represents a pipe with adjustment of a stream of the air passing through it, and serves to operate only amount of the air submitted to cylinders of the engine.
The lower part of throttle knot is warmed up by cooling liquid to exclude its icing during winter time.
The adjusting screw is located in the top part of throttle knot. The sensor of provision of a butterfly valve is connected to a butterfly valve axis.
At operation of the engine on frequency of rotation of idling of a ratio of air and fuel it is regulated by a control system which consists of the control unit of the engine (PCM), the valve of a control system of frequency of rotation of idling (IAC) and other sensors (ECT, IAT, TPS, MAP, MAF), working together with electronic system of injection of fuel (EFI). The valve of a control system of frequency of rotation of idling (IAC) becomes more active depending on operating conditions of the engine (inclusion of central air of air, operation of the amplifier of a steering, temperature of external air). This valve regulates amount of the air submitted to cylinders of the engine bypassing a butterfly valve. Thanks to it, at engine warming up, even at the closed butterfly valve, air arrives in engine cylinders, regulating frequency of rotation of idling. The inlet collector also reduces pulsations of an air stream.
The system of electronic control operates fuel injection, an ignition advancing, diagnostic system and other systems.
The fuel system consists of the following components:
– fuel pump;
– regulator of pressure of fuel;
– fuel filter;
– distributive fuel highway;
On models till 2001 2 fuel filters are established: the main — on the left side of a motor compartment, and additional — in the block of the fuel pump/fuel level sensor.
On models since 2001 1 fuel filter in the block of the fuel pump/fuel level sensor is established.
Nozzles dose out and spray fuel. When giving tension the needle rises by a solenoid winding, passing fuel. The amount of fuel is defined by duration of an impulse during which the nozzle is open.
The main relay of the fuel pump is located in the block of relays/safety locks in a motor compartment and copes on two electric chains. On the first chain management is carried out from the control unit by the engine (PCM), and on the second — from the ignition lock. If after inclusion of ignition engine start is not carried out, the PCM block will disconnect the relay of the fuel pump through 2 pages. Further, at engine start, after the first impulse from the sensor of provision of a camshaft of the relay turns on the fuel pump.