Ignition System: Testing and Inspection
a) Secondary ignition display- Adjust secondary ignition display at oscilloscope. Connect test leads according to manufacturer's instructions.
NOTE: If a fault is displayed for all cylinders, the fault is located in the primary or secondary circuit from the ignition coil to the distributor rotor. If a fault is displayed for one cylinder only, the fault is located after the distributor rotor.
Primary resistor: Terminal 1+15 = O.4-O.6 Ohms
Secondary resistor: Terminal 1+4 = 5-7.2k Ohms
b) Spark plug connector (Ohms)
Suppression resistor: 3k Ohms
- Visually inspect for damage, traces of burning etc.
c) Distributor
Distributor rotor, distributor cap:
Suppression resistor: 1k Ohm each.
- Visually inspect for damage, dirt, faulty mounting position.
d) Ignition timing test
Ignition timing is tested with the engine at operating temperature:
- Using System Tester 9288, ignition timing and engine speed can be read directly in the "Actual values" menu item.
Test values:
With manual transmission
At 840 ±40 rpm ...1O° ±3°
With Tiptronic
At 880 ±40 rpm... 10° ±3°