So Much Hot Air
Brother of The benz, JRBrown
Do you mean to tell me that after all of that hot air I directed at your problem I was way out in left field?
If all things are within spec and the plugs are relatively new(30K miles ?), maybe the cap just wore out.
I can't read between the lines to determine why it did what it did.
Your spark plugs at the 9 heat range is normal for a 103983 engine.
I use the cheap kind, copper core Champion RS9YC and they are resistor type gapped at 0.052 inches with a Jacob's Omni-Magnum Electronic Ignition.
I am going to revert to OEM ignition to-day, removing the Jacob's unit.
I've made other mods to the engine and I want to see what the Jacob's unit really provides me as it was the first change I made many years ago. Jacob's was new on the block then and I'm sure thier products have improved over the years.
Replace the ignition components completely and you will be as new again and at piece of mind.
Happy Trails Beep Beep from The Spiderman in Houston!!!