I have a Mitsubishi Sigma of doubtful heritage (it appears to have an engine older than the body...) which keeps burning out plugs and leads - why ?
BTW, it leaks a LOT of oil, I mean a LOT, more even than most Sigmas, like about 1.5L of oil for every 15L of fuel. The gaskets are worn for sure.
I was wondering if a coked up head causes plugs to burn out ?
Old cars (pre-1960) needed de-cokeing, was this why ?