I was driving the other day and my car started to stumble, from the engine bay I heard a clicking sound. I pulled over and looked under the hood and noticed that my #7 wire was arcing to the block. At the time I have Taylor 8mm Spiro wires, Stock AC Delco plugs and A Jacobs Pro Street Ignition. All these parts have less than 5k miles on them. I pulled my car into the garage and replaced the #7 wire which had no visible damage, and disconnect the Jacobs and hooked back the system to the stock coil. The car stopped stumbling but in the dark you could see blue electricity traveling from the opti, to the coil, to the #7 wire all the way to the plug! None of the other wires show any electricity. It was running fine untill today when the car got to operating temprature it started to stumble again, not as bad as last time but noticible at idle, kind of like I'm missing on the #7 cylinder. I see no arcing and I can nor hear any arcing. Any ideas whats wrong? Opti? #7 plug? Thanks!

 

Anybody?