All carbureted engines and the 1.4L injection engine are equipped with a transistorized ignition system. Engines with a fuel injection system are equipped with an electronic ignition system. The ignition system consists of:
- spark plugs
- ignition cables
- ignition coils
- ignition distributor with slider, Hall sensor and control device
The voltage generated in the ignition coil is fed through the distributor runner and ignition cables to the appropriate spark plugs. A spark jumps on the electrodes of the candles, which ignites the fuel-air mixture in the cylinders. The ignition timing should automatically shift in the direction of early ignition as the engine speed increases. This displacement in the transistor ignition system is carried out in the distributor due to centrifugal weights and due to vacuum (vacuum hose from intake pipe to ignition distributor). In the electronic ignition system, a microprocessor integrated in the distributor calculates the optimum ignition timing depending on the engine speed and load. In addition, the processor provides ignition off. The task of the distributor is to distribute the ignition current in a given order between the cylinders, and using the Hall sensor to provide information about the number of revolutions and the moment of ignition to the ignition control device.
Engines with a fuel injection system are equipped with an electronic ignition system. The ignition control unit is integrated with the injection control unit. The microprocessor controls the ignition timing based on the characteristics field recorded in its memory.
In a parametric ignition system, the optimal ignition timing depends on the condition of the engine. The parameters are the number of revolutions, the temperature of the engine and the degree of load (throttle position and air intake). This refers to the momentary load of the engine, since there is a difference if the car at 4000 rpm is going uphill or downhill.
The required characteristics for the ignition system are determined during bench testing and then matched with real-world tests, so that the optimum value for fuel consumption, exhaust gas composition and driving performance is achieved. The values thus determined are stored in the controller's memory.
Attention! When working on the ignition system, safety precautions must be observed.