5.2. Multipoint system of injection of fuel (MFI)
The multipoint system of injection of fuel (MFI) consists of sensors which determine a condition of operation of the engine, the control unit by the engine (ESM) which operates actuation mechanisms on the basis of information from sensors. The control unit the engine (ESM) operates nozzles for direct injection of fuel, supply of air at operation of the engine in a mode of idling and regulates a corner of an advancing of ignition. Besides, the control unit the engine (ESM) is equipped with several diagnostic functions which simplify search of malfunctions.
Management of fuel nozzles
Management of the moment and time of opening of fuel nozzles is carried out so that the optimum ratio of air and fuel on all operational power setting was supported. In the inlet channel of each cylinder one fuel nozzle is established. Fuel from a fuel tank moves under the pressure created by the fuel pump and an adjustable regulator of pressure. Thus, fuel is stably distributed to each fuel nozzle. Injection of fuel is carried out by each nozzle once for two turns of a cranked shaft, in sequence of operation of cylinders 1-3-4-2. The control unit enriches with the ESM engine a fuel mix, working on "not closed cycle" at warming up of the engine and work under high loading. Besides, at operation of the hot engine at normal loadings the control unit operates the ESM engine a ratio of a toplivnovozdushny mix on the basis of signals from the warmed sensor of oxygen in a mode of "the closed cycle", for ensuring normal work of three-componental catalytic converter.
Management of frequency of rotation of a cranked shaft idling
Frequency of rotation of a cranked shaft is idling supported at an optimum level by supply of the additional air passing bypassing a butterfly valve, according to changes of conditions and engine loadings. The control unit the ESM engine operates frequency of rotation of a cranked shaft idling (ISC), supporting previously the set frequency depending on temperature of cooling liquid and loading from air central air. Besides, when the switch of central air of air is switched off, while the engine works in an idling mode, giving of additional amount of air bypassing a butterfly valve is regulated to avoid fluctuations in frequency of rotation of the engine.
Management of a corner of an advancing of ignition
The switchboard of capacity
located in a chain of a low voltage of system of ignition opening and being closed operates a current proceeding in primary winding to the coil of ignition.
The switchboard operates corner installation an ignition advancing to provide an optimum angle of an advancing of ignition on all operational power setting. Corner installation an advancing of ignition is defined by the control unit the ESM engine depending on frequency of rotation, volume of arriving air, temperature of cooling liquid and atmospheric pressure.
Additional functions of management
1. Management of the fuel pump.
Turns on the relay of the fuel pump so that the current was delivered to the fuel pump at start and in the course of operation of the engine.
2. Management of the relay of the coupling of the compressor of the conditioner.
Switches on and off the coupling of the compressor of the conditioner.
3. Management of the relay of the fan of a radiator.
Frequency of rotation
of the fan of a radiator and the condenser cope depending on temperature of cooling liquid and speed of movement of the car.
4. Management of catching паров fuels.
- At failure detection in one of sensors or the executive mechanisms connected with engine management, as the prevention of the driver the control lamp of CHECK ENGINE/MALFUNCTION INDICATOR will light up.
- At failure detection in one of sensors or executive mechanisms, in memory the diagnostic code of malfunction will be written down.
- The diagnostic code of malfunction in the ESM block which is connected with sensors and executive mechanisms can be считан the special device.
Test by a method of modeling of movement
At tests by a method of modeling pull, bend, pull and twist electroconducting of each of sensors to define a place of faltering malfunction.
- Shake the socket up and down, and also to the right and to the left.
- Shake a plait of wires up and down, and also to the right and to the left.
- Create vibration about an element or the sensor.
Inspection service at a safety lock peregoraniye
a safety lock and will measure resistance between the party of loading of the fused safety lock and "weight". Turn on all switches located in this electric chain. If resistance is equal to zero, means, there is a short circuit between these switches and loading. If resistance on equal to zero, means, short circuit is absent and the safety lock fused as a result of short-term excess of a current.
Main reasons of short circuit.
- Plait of wires pressed by elements of a body of the car.
- Damage of an external casing of a plait of wires as a result retyranny or heating.
- The water which has got to the socket or an electric circuit
- Individual mistake.