6.2.5.3. Models of 2,0 l
The system of injection of Motronic fuel is a joint system of ignition and injection of fuel. Turns of idling are run by the valve which changes amount of the air given to a round of a butterfly valve. The valve is run by the ECU block, adjustment of turns of idling is impossible.
The corner of an advancing of ignition is established by the ECU block depending on turns of the engine and loading, temperature of the engine and temperature of the air coming to the engine. Information on turns of the engine comes to the control unit from the inductive sensor fixed sideways the block of cylinders of the engine. About the sensor there pass the pins fixed on a counterbalance of a bent shaft about the piston of the first cylinder. When passing pins about the sensor in the sensor there is an electric impulse which is transferred to the control unit.
On models with 8 valves till 1990 the system of injection of Motronic ML4.1 fuel was installed. The system of injection of fuel is similar to system of injection of LE/L3 fuel – Jetronic which were established on model of 1,8 l. The control unit is located behind finishing in deepening for the driver's legs.
On models with 8 valves since 1990 the system of injection of M1.5 Motronic fuel was installed. In system of injection of fuel the consecutive system of injection at which nozzles inject fuel in pairs, but not at the same time, as on earlier used system of injection of fuel is used. The fuel pump is located in the fuel tank, but not installed near the fuel tank.
On models with 16 valves the system of injection of M2.5 Motronic fuel was installed. One of the most essential differences of this system consists in a method of measurement of amount of the air coming to the engine. The sensor of a stream of air represents the wire which is energized. The sensor sends constantly changing tension signal corresponding to the mass of the air passing in the engine.
On the basis of signals of the sensor of a detonation the corner of an advancing of ignition is regulated and at the same time there is no need for a fuel octane number cap.
In system of injection of M2.5 fuel the consecutive system of injection at which nozzles inject fuel independently from each other is used. The ECU block operates a fuel nozzle, changing the impulse width, that is an interval of time when the nozzle is open to provide richer or poorer fuel mix.
On all systems of injection of fuel if there is a mistake in any of the data obtained from sensors, the ECU block enters a way of the doubler. In this case the ECU block ignores the wrong signal of the sensor and accepts previously programmed value which allows the engine to continue work, though with smaller efficiency. If ECU is included into a way of the doubler, then the lamp of the alarm system on a combination of devices lights 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.