4.3.3. Systems of injection of fuelSystem of injection of ECU fuel – the self-adjusted system which controls and stores the data providing optimum operational power setting at various loadings.
At shutdown of the accumulator there is a deleting of data and for their restoration it is necessary to start the engine and to take it idling until the system is customized. This process will be better executed when carrying out the road test within 15 minutes at 2500–3500 revolutions per minute.
ELEMENTS OF SYSTEM OF INJECTION BOSCH L3. L (JETRONIC)
System of injection of Bosch L3 fuel. l of faltering type working under low pressure. Fuel moves the fuel pump via the filter on the highway to injectors. The pressure regulator installed at the exit of the fuel highway and connected with vacuum in inlet a collector supports constant pressure in nozzles, returning excess fuel in the fuel tank.
The quencher of impulses on an entrance of the fuel highway reduces fluctuation of pressure of fuel.
The electronic control device (ECU) and the measuring instrument of a stream of air are installed on a casing of the air filter. ECU uses signals from various sensors to define time of opening of injectors for any operational mode.
The electronic control device receives the following signals:
– amount of the air consumed by the engine, and passing through the measuring instrument of an air stream;
– air temperature;
– frequency of rotation of the engine and angular provision of a bent shaft;
– provision of a butterfly valve.
Nozzles work at the same time, spraying fuel towards the inlet valve.
The additional air channel provides additional air supply in the mode of start of the cold engine.
ELEMENTS OF SYSTEM OF INJECTION BOSCH LU2 JETRONIC
The principle of action of the LU2-Jetronic system is similar described for the L3 system. l-Jetronic (see above), but with the following distinctions:
– the case of a butterfly valve has the only camera;
– there is an oxygen sensor;
– there is a catalytic converter.
The most essential distinction – the fact that the LU2-Jetronic system has the oxygen sensor in system of release which allows the electronic control device to execute mix regulation that gives the chance to use catalytic converter.
ELEMENTS OF SYSTEM OF INJECTION BOSCH MOTRONIC OF MP 3.1
Principle of action of the Bosch Motronic MP3 system. l is similar described for the L3 system. l-Jetronic (see above), but with the following distinctions:
– ECU operates system of ignition in addition to system of injection of fuel, creating the integrated control system of the engine;
– the system of distribution of ignition is reduced;
– instead of the measuring instrument of a stream of air the sensor of air temperature and the sensor of pressure in a collector is used.
ELEMENTS OF SYSTEM OF INJECTION BOSCH MOTRONIC M. 1.3
Principle of action of the Motronic MI system. 3 it is similar described for the L3 system. l-Jetronic (see above), but with the following distinctions:
– ECU operates system of ignition and system of injection of fuel, creating the integrated control system of the engine;
– the sensor of provision/frequency of rotation of the engine is used for obtaining information on the provision of a bent shaft and the frequency of rotation of the engine;
– ECU operates idling speed on all operational modes via the adjusting valve of speed of idling;
– the sensor of oxygen is used to allow ECU to operate fuel mix very precisely that allows to use catalytic converter;
– the detonation sensor installed in the block of cylinders is used for detection of the beginning of a detonation or premature ignition. It allows ECU to choose an optimum advancing of ignition for the prevailing operational modes of the engine without risk of damage of the engine.
ELEMENTS OF SYSTEM OF INJECTION BOSCH MOTRONIC ML4. L
– ECU includes function of start from a cold state and memory of damage;
– the screw of contour of regulation of mix is replaced with a potentiometer of provision of a butterfly valve;
– the case of a butterfly valve has the double camera;
– speed of idling is supported at the predetermined level (irrespective of loading) by the idling speed valve.
ELEMENTS OF SYSTEM OF INJECTION BOSCH MOTRONIC OF MP 5.1
Control system of the Bosch Motronic MP5 engine. l (ignition / system of injection of fuel) includes catalytic converter and a control system of release of vapors of fuel and conforms to the latest standards of control of issue.
The fuel pump which is shipped in the fuel tank provides supply of fuel via the filter installed behind under the car bottom. Pressure in fuel system is run by pressure regulator in the fuel highway.
The electric control system consists of ECU along with the following sensors:
– potentiometer of provision of a butterfly valve;
– sensor of temperature of cooling liquid;
– the sensor of temperature of the arriving air;
– the lambda sensor – reports to ECU the content of oxygen in exhaust gases;
– sensor of provision of a bent shaft;
– pressure sensor in an inlet collector;
– vehicle speed sensor.
ECU operates fuel nozzles, changing the impulse width (an interval of time when nozzles are open). Fuel mix constantly changes ECU to provide an optimum ratio for start of the hot or cold engine, warming up, the mode of idling and acceleration.
ECU also determines idling speed through an auxiliary pneumatic valve which bypasses a butterfly valve.
The electric element of heating is attached to the injector case that at start of the cold engine prevents possible frosting.
If there is a mistake in any of the data obtained from the sensor, ECU is included into a way of the doubler. In this case ECU ignores the wrong signal of the sensor and accepts previously programmed value which will allow the engine to continue work (though with smaller efficiency). If ECU is included into a way of the doubler, the lamp of the alarm system on the dashboard will light up and damage will be written down in memory of ECU. After that it is necessary to carry out full test of a control system of the engine, using the special electronic diagnostic test bench which just turns on in the diagnostic socket of system.
ELEMENTS OF SYSTEM OF INJECTION MAGNETI MAREILLI 8P
The control system of the Magneti Marelli 8P engine (ignition / system of injection of fuel) is very similar in operation on the Bosch MP5 system. l (see above), except an idling speed control system.
On the Magneti Marelli system the speed of idling is operated by ECU via the additional engine attached to the case of a butterfly valve.
The engine has the pusher operating opening of the additional channel which bypasses a butterfly valve. When the butterfly valve is closed, ECU operates the movement of a pusher which regulates amount of air which passes through the channel of the case of a butterfly valve, and operates idling speed. The roundabout channel is also used for additional supply of air at start of the cold engine.