BMW 5 series E39

Since 1996-2001 of release

Repair and car operation

Ignition system

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

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

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

The ignition moment depends also on the data received from the gauge of a detonation. As the fuel expense is minimum at higher degree of compression, in modern engines compression degree is established by the maximum. On the other hand high degree 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 gauge of a detonation registering occurrence of a detonation and transmitting a signal about it in the block of management which in turn displaces the ignition moment in a direction of later is established. Engine BMW has two gauges of a detonation located in the block of cylinders. One gauge registers a detonation in cylinders 1-2-3, another in cylinders 4-5-6. Presence of the gauge of a detonation allows to apply less детонационностойкое fuel (gasoline АИ-91). It is necessary to mean, however, that it leads to decrease in capacity of the engine. Application of gasoline АИ-98 leads to increase of capacity of the engine.

At work with electronic system of ignition it is necessary to observe corresponding security measures for an exception травмирования people or system damages.