Ignition System Check

1. Check distributor cap for damage, dirt, burning or carbon tracking. Replace if necessary.
2. Check distributor cap center tower resistance with suitable ohmmeter. Resistance should be 1000 ohms.
3. Ensure rotor is a snug fit on distributor shaft, then check rotor resistance. Resistance should be 1000 ohms.
4. Check spark plug connectors for damage, then check connector resistance. Resistance should be 3000 ohms.
5. Check ignition coil primary resistance by measuring between terminals 1 and 15 with ohmmeter. Resistance should be .4 - .6 ohms on 924 and 944 models, or .4 - .7 ohms on 911 models.
6. Check ignition coil secondary resistance by measuring between terminals 1 and 4 with ohmmeter. Resistance should be 5000 - 7200 ohms on 924 and 944 models, or 5000 - 8700 ohms on 911 models.
7. On 911 models, check that plug on top of ignition coil is not missing. If plug is missing or casting compound has run out, replace ignition coil and control unit.