So, I went for a little drive in the A a while ago and she seemed like she lost a little power. When I got back I disconnected the spark plug connectors and placed them 1/8" or so above the contacts on the distributor cap. Three had a nice strong steady spark, one did not. #3 was not firing or only firing once every few minutes. I took the distributor cap off and cleaned all 4 contacts, not much better. Checked that the plug was tight no better. Any idea why there would be no spark (intermittent) to only one plug? Distributor cap bad, plug bad?