Ignition system. General information (BMW 5 Series E34)

The ignition system produces an ignition spark, which ignites the air-fuel mixture in the cylinders at a certain moment. To produce an ignition spark of sufficient power in the ignition coil, the battery voltage of 12 volts is converted to a voltage of up to 25,000-30,000 volts.

A diesel engine does not require an ignition system, since due to the high compression ratio, the air is heated to such an extent that after fuel injection, it begins to ignite spontaneously.

BMW petrol engines are equipped with a parametric ignition system, the operation of which is controlled by the Motronic control unit. The Motronic control unit also electronically controls fuel injection.

The ignition system consists of:

• ignition coils (on the M50 engine, an ignition coil is installed on each cylinder),
• spark plugs,
• high voltage ignition distributor with runner (on the M50 engine is missing),
• position sensors,
• dME control unit (DME = digital engine management system - Motronic).