7. System of ignition

On cars the contactless system of ignition like DLI is installed.

The system includes:

      – two separate blocks of coils of ignition;
      – the sensor of an angle of rotation of a bent shaft transferring to the control unit of the engine information on the frequency of rotation of a bent shaft;
      – the control unit of ignition which is built in the control unit of the engine;
      – the sensor of position of the camshaft transferring to the control unit of the engine information on an operating procedure of cylinders;
      – high-voltage wires and spark plugs.

Work of system of ignition

In usual system of ignition, the coil of ignition develops a high-tension current, and the distributor of ignition transfers this current, to the required time, to the corresponding spark plug.

In contactless system of ignition the sensor of position of the camshaft and the sensor of an angle of rotation of a bent shaft, transfer to the control unit of the engine information to what cylinder it is necessary to give ignition tension. The control unit of the engine gives a signal to the corresponding coil of ignition which develops a high-tension current and transfers this current to a spark plug.

In contactless system of ignition the impulse of ignition moves on two spark plugs, one on a compression step at once, one on an exhaust step – the ignition spark on a step of an exhaust does not render any value on operation of the engine and therefore it is spent for nothing. Cylinders are grouped according to an operating procedure of cylinders. For example, in Sephia an operating procedure of cylinders – 1–3–4–2. Each coil of ignition actually consists of 2 separate high-voltage windings which give a spark to two cylinders everyone (one to cylinders No. 1 and 4, and another to cylinders No. 2 and 3).

Electronic system of an advancing of ignition

Installation of a corner an advancing of ignition is defined and established by the control unit of the engine based on signals from various sensors and switches.

The control unit of the engine changes installation of a corner an ignition advancing according to the frequency of rotation of the engine, amount of the arrived air, temperature of cooling liquid and other conditions.


Prevention

Ignition advancing corner at an idling frequency: 8±5 ° to VMT
The corner of an advancing of ignition is not regulated.


Components of system of ignition

The mechanical distributor of ignition is replaced with the electronic control unit which does not have mobile parts.
In system of ignition two coils of ignition located on the engine over spark plugs 2 and 4 of cylinders are used.

Resistance of the coil is identical for two coils of ignition. Coils of ignition do not demand service and, with defects, are subject to replacement.

High-voltage wires connect ignition coils to spark plugs. They perform functions generally same, as on usual system of ignition. Because of their shorter length the energy transferred to spark plugs increases.

The spark plug serves for transfer of a high-tension current of the ignition developed in the coil, to electrodes in the combustion chamber where this current makes the spark category for ignition of fuel-air mix.