BMW 5 Series E39

since 1996-2001 release

Repair and operation of the car

+ Introduction
+ Maintenance instruction
+ Current leaving and service
+ Engine
+ Cooling systems, heating
- Power supply system and release
   + Power supply system
   - System of injection of the petrol engine
      Memory of malfunctions
      Security measures and rules of respect for purity during the work with system of injection
      Work of system of injection
      Check of systems of ignition and injection
      Adjustment of the drive of gas
      Removal and installation of a branch pipe of a butterfly valve
      Removal, check and installation of the valve of adjustment of idling
      Check, removal and installation of the sensor of temperature
      Check of injectors
      Removal and installation of injectors
   + Power supply system of the diesel engine
   + System of production of the fulfilled gases
+ Engine electric equipment
+ Manual transmission
+ Automatic transmission
+ Coupling and power shafts
+ Brake system
+ Suspension bracket and steering
+ Body
+ Onboard electric equipment
+ Schemes of electric equipment
+ System of onboard diagnostics

Work of system of injection

Fuel is sucked in from the fuel tank by an electric gasoline pump and moves via the fuel filter to the distributive highway and further to injectors. Pressure regulator at the distributive highway watches that pressure of fuel made 3.5 bars. Injectors have electric management and inject fuel pulsewise into the inlet pipeline in front of inlet valves.

Air is soaked up by the engine via the air filter and passes through the measuring instrument of mass of air. In the case of the measuring instrument there is a thin, electrically warmed plate which is cooled with the passing air stream. The control system changes value of current of heating so that temperature of a plate remained a constant.

If, for example, the amount of the soaked-up air increases, the plate seeks to be cooled. Thereof value of current of heating of a plate grows. The control system of the engine determines a stream of air and, therefore, its loading by heating current deviations.

The control unit depending on the mass of air and speed of the engine defines time of injection and, thus, amount of injectable fuel. At longer opening of injectors the amount of injectable fuel increases. Additional sensors monitor the correct supply of fuel in extreme situations of the movement of the car.

The injection of fuel happens consistently. It means that injectors cope individually, and the sequence of injection corresponds to the sequence of ignition. By means of the choice of the moment of injection in relation to the moment of opening of inlet valves it is possible to regulate parameters of the fulfilled gas and engine capacity.

The potentiometer of a butterfly valve is on a gate shaft. He transfers to the control unit information on position of the gate. Thanks to it, in particular, process of compulsory idling since so far the gate is closed copes and at the same time speed lies above some certain value, the control unit stops supply of fuel to the engine.

The relay of the fuel pump is in the relay block behind the left depreciation rack. The relay gives current to the fuel pump. The safety switch interrupts supply of fuel at the idle engine, for example, if the engine decayed.

The provision of a bent shaft of the engine and its speed are defined by two inductive sensors. The sensor of speed is at a pulley of a bent shaft. The sensor of recognition of the cylinder is in a forward part of the engine in a distribution drive chain box cover.

Two sensors of oxygen measure the content of oxygen in the fulfilled gases and transmit a signal to the control unit. On the basis of the obtained information the control unit changes a ratio fuel/air that provides optimum reburning of fuel mix.

The regulator of idling operates amount of air idling bypassing a butterfly valve. It provides maintenance of constant speed idling irrespective of connection of additional consumers, such as, of the power steering or the compressor of cooling.

The electromagnetic valve of ventilation of the fuel tank is operated depending on a condition of the engine. Vapors of gasoline which are formed in the fuel tank accumulate in an adsorber and via the electromagnetic valve move in the combustion chamber. Gasoline vapors, thus, are effectively used and do not get to the atmosphere.

The control system of the camshaft, in abbreviated form VANOS, turns a shaft of inlet valves by means of oil pressure in relation to driving appreciate depending on speed and loading of the engine. It allows to receive optimum time of opening of valves concerning comfort of idling, the characteristic of torque and fuel consumption. The DME block operates an oil stream to an adjusting element by means of the electromagnetic valve.

Control of tension ignition at too low voltage switches-off the DME block (for example, owing to damage of a cable). At the same time the engine cannot be started. It excludes damages of the catalytic converter.

Contact with other monitors (ABS, ASC, control of the check point) is exercised through CAN, representing the special tire of data. This system, except other, has that advantage that the plait of cables of the engine contains smaller quantity of cables. Such tire provides higher degree of protection of the car at failure of separate devices.