Ignition system — brief description (Mercedes-Benz S-Class W116)

Structurally, ignition distributors are the same for all engine types. The distributor is equipped with a centrifugal and vacuum regulator, a vacuum regulator with a double chamber for setting the early and late ignition timing. To improve the composition of exhaust gases in idle mode and low-speed driving, the ignition timing is shifted in the "late" direction. In the ignition system, an additional resistance is included between the ignition coil and the battery. The resistance increases the durability of individual components of the ignition system. When the engine is started by the starter, to ensure maximum current in the starter circuit, the additional resistance is disconnected when the key in the ignition switch is turned to the start position. After the starter is turned off, the additional resistance is again included in the circuit.

The ignition distributor is the most important part of the engine and the gaps between the breaker contacts directly affect the operation of the engine, so they must always correspond to the prescribed values. For optimal adjustment, it is recommended to contact a service station, where they can carry out and adjust the angle of the closed state of the breaker contacts, adjust the centrifugal and vacuum regulators. To perform this work, special tools and devices are required, and we do not recommend doing it yourself. If you suspect that the distributor is worn out or the adjustment is out of order, no additional checks should be carried out.



Engines with fuel injection systems are equipped with a transistor ignition system. Instead of breaker contacts, a transistor circuit switches on the current in the ignition coil. The breaker contacts control this transistor circuit. When the contacts are closed, the transistor is closed and the current in the ignition coil is interrupted. Interrupting the current in the primary winding circuit of the ignition coil induces voltage in the secondary winding, as in a conventional ignition coil. To increase the ignition voltage when starting the engine, an additional 0.4 Ohm resistor is bridged by contact 16 on the starter. When working with the ignition system, certain safety rules must be followed.

[Material taken from a web resource: Mercedesman.ru]