Audi 80/Avant (B4)

since 1991-1995 release

Repair and operation of the car

If to construct the chart of dependence of a corner of an advancing on loading and speed of the engine, then the so-called characteristic of ignition will turn out. Than stranny its form looks, more precisely ignition is coordinated by that with the corresponding operational situation of the engine.

• The basic principle of ignition consists that current from the rechargeable battery arrives at first on primary winding of the coil of ignition.
• This winding consists of several rounds of a thick wire. Under the influence of a current around the iron core in the coil of ignition there is a powerful magnetic field – the energy coming to system for ignition.
• If the piston approaches a point in which the arrived and compressed mix has to ignite – to the ignition moment, – current in the coil of ignition is interrupted. It occurs at the command of the control unit in the electronic switchboard of system of ignition.
• At shutdown of current magnetic field in the coil of ignition is interrupted. At the same time there is a following: in the secondary winding consisting of very large number of rounds of a thin wire there is an impulse of a high-tension current size in several tens of thousands of volts.
• This secondary tension of system of ignition arrives via the distributor (at models with the 6-cylinder engine directly) on that spark plug which sequence approached in an operating procedure of cylinders of the engine. Mix ignites, the engine is turned further. The electrochain becomes isolated, process repeats.