Spark test
1. The spark test can only be carried out on vehicles without a catalyst, as the catalyst can be destroyed by infiltrating the exhaust system and flammable fuel.
Attention! When starting, do not hold the ignition cable with your hand. Use well-insulated pliers for this or fix the cable in the desired position on the cylinder block with adhesive tape.
2. Disconnect the ignition cable from the ignition coil at the distributor.
3. Hold the ignition cable with well-insulated pliers at a distance of 5-10 mm from the ground. Use only highly conductive metal parts as ground, such as the cylinder block.
4. Ask an assistant to start the engine. There should be powerful blue sparks. If the spark does not jump, you should check the current supply to the coil.
Checking the current supply
1. Disconnect the plug from the ignition coil and, with the ignition on, check the voltage at the positive terminal. The voltage should be 12V. If there is no voltage, check the main fuse and cable harness.
Checking the primary winding
1. Measure the resistance between the terminals with an ohmmeter and compare with the value in the table.
Checking the secondary winding
1. Using an ohmmeter, measure the resistance between the positive terminal and the high voltage terminal, compare the obtained value with the value in the table.
Required values
Engine | Primary voltage | Secondary voltage | |
All engines up to 9/89 y. | infinity | 6 - 30 Ohm | |
Carburetor engine and injection engine (VZ) since 10/89 issue. | 1 | 0.77 - 0.95 ohm | 10 - 16 ohm |
2 | 0.9 - 1.1 ohm | 10 - 16 ohm | |
injection engine (BP, B6) since 10/89 issue. | 0.81 - 0.99 ohm |
2. If the result of one or both checks does not correspond to the required value, the ignition coil should be replaced.