Make sure that the vacuum advance diaphram is not punctured.
Adjust the ignition timing for proper performance. This can make a significant difference.
Vacuum leaks in the intake side of the engine can be misdiagnosed as ignition problems.
Check ignition wires (distributor to spark plugs) with a digital ohm meter to determine serviceability.
Once a spark plug is fouled it is trashed. Do not clean spark plugs with a wire brush.
Always check the gap on spark plugs you install in your car. Spark plugs are pre-gapped at the factory, the problem with this is it is not the specification for your car!
