RKA

Let's suppose one of the ignition wires got old and rotten...eventually leading to the point where there was infinite resistance between each end of the wire (resulting in a misfire condition for an unknown period of time). Is it possible that the ignition coil might be damaged if the spark energy doesn't make it to the plug?

JWG

on one cylinder on each bank due to the dual-ended coils that use a "waste spark" system. That means, when the coil fires a spark gets made in both cylinders simultaneously: one at to top of an ignition (compression) stroke and one at the top of (or at least during) an exhaust stroke.

RKA

but the ignition system was similar to the Audi V6's. One ignition coil sending spark to 2 cylinders. A plug/wire swap still left a pretty weak spark on one pair of cylinders, so I swapped the corresponding ignition coil, and it runs smooth now. I was just trying to establish some cause and effect (why the coil failed), but it appears it was just age. One of the other coils is getting weaker, but it's solid enough for the time being...since I'm not getting any misfiring on those cylinders yet.

Thanks for the thoughts!