Audi 80 Quiz
Ignition System

Various ignition systems

In this manual: Ignition System
Technical Description — 39Engines — 41Exhaust System — 13Cooling System — 28Fuel tank and fuel pump — 12Air Filter and Intake Ducts — 13Mono-Motronic Injection System — 18Digifant Injection System — 19KE-III-Jetronic Injection System — 35MPI and MPFI Injection Systems — 32Clutch — 11Transmission and Driveline — 21Suspension and Steering — 33Brake System — 41Anti-lock brake system — 8Wheels and Tires — 13Body Electrical System — 35Ignition System — 24Lighting — 14Signaling Devices — 7Instruments and Auxiliary Equipment — 54Heating and Ventilation — 7Body Components — 18Troubleshooting — 6Specifications — 13
~2min read

The ignition system is, on almost all Audi 80 models, an integral part of the electronic engine management system. What appears complex on paper is actually relatively simple: on models with 4- and 6-cylinder engines, the ignition system is controlled by the same control unit as the fuel injection system. This has the advantage that the reactions of both systems can be optimally coordinated with each other. In addition, the same sensors can be used for mixture formation and ignition timing control (as already described). The following ignition systems are fitted to various Audi 80 models:

Mono-Motronic ignition system for the 66 kW engine. Even in this simplest version, ignition timing control, that is, matching ignition timing to the respective operating conditions, is performed exclusively by electronics.

The Digifant ignition system is fitted to 85 kW engines. Its operating principle is the same as that of the Mono-Motronic system: everything is contained in one control unit, and ignition timing is controlled by electronics.

The fully electronic ignition system (VEZ) is fitted to the 5-cylinder engine rated at 98 kW. Although this ignition system has its own control unit, the ignition and injection systems constantly exchange data with each other. Ignition timing is controlled by electronics.

The MPI or MPFI ignition systems for 6-cylinder engines are also an integral part of the engine electrical system. Special feature: these systems operate without a distributor. Accordingly, one ignition coil serves each pair of opposing cylinders, which produces a spark only when it is required by one of the cylinders. For technical reasons (parts economy), each cylinder receives one additional (unneeded, but harmless) spark per engine revolution during the exhaust stroke.

Note: as already mentioned, various ignition systems have many features in common. The ignition systems of 4- and 5-cylinder engines are almost identical. For example, the high-voltage components in which the spark is generated are almost the same in these systems. Significant differences exist only with the ignition systems of 6-cylinder engines.

Test yourself

A quick Audi 80 quiz: every answer comes with an explanation and a link to the manual page.