Ignition timing angle (Audi 80 B4)

The ignition timing of the air-fuel mixture in AUDI 80 cars with an electronically controlled ignition system cannot be adjusted. At the same time, when checking idle speed and CO content in the exhaust gases, workshops also check the ignition timing. For this purpose, a survey of the self-diagnostic system is performed. After that, the control unit is set to the basic adjustment values, which is only possible with the help of a device for reading faults. The fact is that the ignition system control unit is "self-learning" and accordingly adjusts to the current situation, adjusting the ignition timing. Therefore, first of all, it is necessary to make sure that there are no faults in the system that negatively affect the ignition timing. The same applies to setting the system to the basic values of the ignition timing. Until the control unit is switched to the basic settings, the correct setting of the ignition timing is impossible. When determining the correctness of the ignition timing, workshops proceed from the data given in the table below. The table contains the test and nominal(installation)data. Verification data is used when performing control checks and has a wide tolerance range. Setup data is used when performing thorough checks and fine-tuning of the system.

Caution! The idle speed sensor and the knock sensor affect the ignition timing. A defective knock sensor can be identified by a delay in the ignition of the mixture of at least 10° after briefly pressing the accelerator pedal and, accordingly, fuel injection.