Checking ignition timing

Ignition timing in the electronically controlled ignition systems of the Audi 80 cannot actually drift out of adjustment. However, during the idle speed test and the exhaust emissions test, the workshop also checks ignition timing. To do this, the fault memory must first be read out. Then the ignition control unit must be returned to basic setting. This is also performed with the fault memory reading tester.

There is no point in adjusting ignition timing yourself without first reading out the fault memory. Since our control units are self-learning, they can carry out the necessary ignition timing correction, for example if the signal from one of the sensors is missing. Before changing anything in the ignition timing, make sure that the ignition timing has not been corrupted by a system malfunction.

The above applies to the so-called basic adjustment using the V.A.G 1551 fault memory reading tester. Until the control unit has been returned to basic setting, correct adjustments cannot be made. For this reason, it is necessary to contact an Audi workshop. They will check the values listed below.

Adjustment data

The table shows one test value and one set value for ignition timing adjustment, which should be understood as follows: for a quick check, use the larger tolerance of the test value. If adjustment is required in any case, it must be carried out thoroughly and, if possible, as close as possible to the set value.

Adjustment data

* No data

Tip: The idle switch and the knock sensor affect ignition timing on vehicles so equipped. A faulty knock sensor can be recognized by ignition timing that is retarded by at least 10° after briefly pressing the accelerator pedal.