E39 series BMW 5

since 1996-2001 of release

Repair and car operation

+ Introduction
+ Maintenance instruction
+ Current leaving and service
+ Engine
+ Systems of cooling, heating
+ Power supply system and release
- Engine electric equipment
   - Ignition system
      Security measures at work with ignition system
      Removal and installation of the coil of ignition
      Removal and installation of the sensor of a detonation
      Check and replacement of the sensor of impulses
      Removal and installation of the tip of a spark plug
      Removal and DME control unit installation
      Spark plugs
   + System of preheat of the diesel engine
   + charge and start Systems
+ Manual transmission
+ Automatic transmission
+ Coupling and power shafts
+ Brake system
+ Suspension bracket and steering
+ Body
+ Onboard electric equipment
+ electric equipment Schemes
+ System of onboard diagnostics

Ignition system

The system of ignition generates sparks which ignite a fuel mix. For ensuring necessary energy of ignition the coil of ignition will transform tension of the storage battery 12 B to tension of 30 000 Century.

The diesel engine has no ignition system. Here thanks to high extent of compression air heats up to the temperature providing spontaneous ignition of fuel at its injection.

Petrol engines of BMW cars are equipped with direct adjustable system of ignition. Management of ignition is carried out by the electronic control unit the engine. The system has no ordinary distributor of ignition. Ignition distribution on cylinders copes the electronic block which does not have mobile parts. Tension of ignition here moves six independent coils of ignition located over candles. Synchronization of ignition is carried out by system by means of the signals developed by the pulse sensor. The sensor is ahead at the block of cylinders. The sensor works depending on number of turns of the engine.
For definition of the necessary moment of ignition the control unit uses the corresponding characteristics of ignition. It allows system of ignition to adapt for various service conditions.

The moment of ignition depends also on the data received from the sensor of a detonation. As fuel consumption is minimum at higher extent of compression, in modern engines extent of compression is established maximum. On the other hand high extent of compression can lead to uncontrollable process of combustion that is shown in an engine detonation. Long influence of a detonation leads to engine damage. For an exception of this phenomenon the sensor of a detonation registering emergence of a detonation and transmitting a signal about it in the control unit which in turn displaces the ignition moment in the direction of later is established. The BMW engine has two sensors of a detonation located in the block of cylinders. One sensor registers a detonation in cylinders 1-2-3, another in cylinders 4-5-6. Existence of the sensor of a detonation allows to apply less detonatsionnostoyky fuel (AI-91 gasoline). It is necessary to mean, however, that it leads to decrease in engine capacity. Application of AI-98 gasoline leads to engine capacity increase.

All elements of system of ignition are coordinated with each other and provide the optimum moment of ignition. Adjustment of the moment of ignition is impossible.

At work with electronic system of ignition it is necessary to observe the appropriate measures of safety for an exception of a travmirovaniye of people or system damage.