The ignition system consists of four spark plugs, high tension wires with spark plug tips and an ignition coil assembly with two coils.
Ignition coils 3 on block 1 are filled with plastic (see illustration 1.0).
The ignition coil assembly together with the built-in 2 spark plug tips is located directly on the spark plugs (see illustration 1.0). Each coil supplies voltage to two spark plugs.
The spark that ignites the fuel-air mixture is generated by spark plugs on command from the engine control unit.
(Original source of information: MercedesMan.ru)
In this case, the voltage distribution to the spark plugs is carried out by electronic components, replacing the usual mechanical ignition distributor with a runner.
The ignition advance angle is not adjustable. If its value does not match the nominal value, then it is necessary to replace the faulty ignition system parts.
The ignition system operates without wear and does not require maintenance. It is only necessary to replace the spark plugs regularly.
Safety precautions when working on the ignition system
To avoid injury or damage to the fuel injection system or ignition system, the following safety precautions are recommended:
- do not touch or remove high voltage wires while the engine is running or starting;
- connect and disconnect fuel injection and ignition system wires only when the ignition is off. The same applies to the wires of measuring instruments used to perform measurements on these systems;
- persons with a pacemaker should not be allowed to perform work on the electronic ignition system;
- do not short-circuit terminal 1 of the ignition coils to ground (-);
- perform a spark test, if necessary, only with the ignition coil assembly removed and the four spark plugs connected, ensuring good ground (-) contact;
- switch off the ignition and disconnect the crankshaft position sensor plug when performing work that requires turning the engine with the starter, such as when checking the compression, to avoid starting the engine;
- it is mandatory that at least one ignition coil assembly socket be connected to ground (-) when testing the system with the coil assembly disconnected. Voltage on the primary winding of the coils can reach up to 400 volts;
- do not connect a tester with a test lamp to terminal 1 of the ignition coil.