Ignition system (6-cylinder engines 2.6 and 2.8 l) (Audi A6 C4)

These engines do not have a distributor. 6-cylinder engines have 3 twin ignition coils. The twin ignition coils are located in front of the cylinder head. They are controlled by the fuel injection system control unit via the voltage output stage, which is mounted on the front wall of the car in the engine compartment. In this case, one twin ignition coil supplies ignition voltage to one pair of cylinders. At the same moment of ignition, the twin coil produces two sparks simultaneously. Moreover, depending on the circumstances, one twin ignition coil supplies high voltage to the pair of cylinders whose pistons simultaneously reach TDC.

Example:

In a 6-cylinder engine, one spark plug produces a spark on the compression stroke of cylinder 1, while the other spark plug simultaneously produces a spark on the exhaust stroke of cylinder 6. Only for this "idle ignition" a voltage of approximately 1 kV is supplied. Therefore, this does not cause increased wear of the spark plugs.

After one revolution of the crankshaft, cylinder 6 is on the compression stroke and cylinder 1 on the exhaust stroke. For cylinders 2 + 4 and 3 + 5, this process is similar.