Diesel does not have an ignition system. Here, the air in the cylinder is compressed to such an extent that its temperature is sufficient to ignite the fuel injected into the cylinder.
All carbureted engines, except for engines with a displacement of 1.3 liters up to 7/84, which have a contact ignition system (UKZ), equipped with a built-in ignition system (IZA). Injection engines equipped with an electronic ignition system (ESA).
The ignition system consists of:
- spark plugs
- ignition cables (BB wires)
- ignition coils (in UKZ system)
- ignition distributor with slider, breaker contacts with vacuum adjustment in the UKZ system
- ignition distributor with runner and Hall sensor, built-in ignition coil and ignition control unit in IZA and ESA systems
In a circuit breaker ignition system (UKZ) the primary current is supplied to the ignition coil through an interrupter.
The high voltage generated in the ignition coil is fed through the ignition distributor to the spark plugs.
With an increase in the number of revolutions, the ignition timing should shift towards the advance. In the UKZ and IZA systems, this is achieved in the ignition distributor by centrifugal weights and a vacuum regulator. In the IZA system, the ignition timing is determined by the microprocessor of the control unit depending on the engine speed and engine load. In addition, the microprocessor monitors the shutdown of the ignition system. The task of the ignition distributor is to supply an ignition spark of a certain sequence to the spark plugs, the formation of a reference signal by the Hall sensor to the control unit to calculate the engine speed and control the ignition timing. Changing the ignition timing is achieved by shifting the base plate with the induction coil of the Hall sensor by a vacuum regulator located on the ignition distributor:
Engines with a fuel injection system have an ESA ignition system, which is a further development of the IZA system. Here, the ignition system control unit is connected to the injection system control unit. This system additionally takes into account air and coolant temperature, air pressure and battery voltage. The microprocessor controls the ignition timing on the basis of the optimal characteristics contained in the memory of the control unit.
Attention: When working on the ignition system, take into account security measures.