Originally Posted by onehundred80
Get a spray bottle with some water in it, go into a dark garage or night time outside, the dark garage is best as it will be much darker. Spray water on the coil packs and wires, not too much. Start the car and switch of the light. With a little luck you will find sparks and pin point the problem.
I've done this and watched a firework display back in the old days, with sparks all over the cables and distributor. 
I've used this test scenario in the past, minus the spray bottle of water, and it's a good test for faulty/worn/old/crappy spark plug wiring and it's harness.
If there is arcing, anywhere in these runs, you should see it.
If you suspect this and go to move spark wires for a cleaner look, with the engine running, put on rubber gloves, cause you will act like a nice big ground and definitly feel the pain...lol...