weird test with spark plugs

[UPnorth362]

Make sure there is not a crack in the coil boot. Also use a very small amount of dielectric grease around the inside of the coil boot. Also something you might look for is if there is a lot of corrosion on the plate inside the coil that contacts the top of the plug.

As for plugs, use either NGK, or Denso. Bosh, Champion, etc are junk. I have used Bosh plugs for other projects in a pinch, and always seem to have problems somewhere down the road.