Hi all,
My 93 z28 is arching from the coil to the the housing or magnet it sits in. Its also arching from the coil wire itself to a hose it sits against. The car has a intermittent misfire once in awhile mostly when warmed up. What would cause it to do that? Any info would be greatly appreciated. Thanks

 

I would look at a defective cracked coil insulation or possible shorted coil first, if it's tested OK then check for other causes.. the coil voltage takes the least resistance path to ground.. It's supposed to be through the spark plug(s). If you have open, burnt or corroded terminal/insulation in the coil to opti or the plug wires, defective cap/rotor or a bad plug the spark can discharge around the coil.

 

Whats the easiest way to test the coil, and how will I know if its bad? Thanks