Well your post there scared me a little so I went and did my own test. I pulled the injector harness off of number 4 cylinder and then pulled the spark plug. I then attached the plug back onto the wire and grounded the plug, and stuck the plug in front of my windshield so I can watch.
Fired the car and the spark almost looked like a flame. So it looked pretty powerful. Well as it was running the spark plug slipped down the windshield and into the engine bay a bit, my ground clip fell off my plug and it started arcing against my hood! It must have been a good 1/2 to 3/4 of an inch and it looked just like those globe things you touch the outside of and the the arc moves towards your hand. It then kinda fell down below the intake, I tried to grab it carfully, well it gave me a couple of good shocks, lol. Im gonna have to say mines working
