You need to find someone who has and can read an ignition scope. It will tell you everything. The secondary ignition patterns can be displayed in different formats. the cylinders are individually displayed and can be compared to each other. Everything that effects an ignition will be displayed from distributor wobble to whether every spoke of the reluctor is triggering. Low voltage, high voltage, low and high resistance can all be seen on the scope. analyzing the arc burn pattern can tell you mixture/fuel problems and a rising burn line means the cylinder is lean. An erratic burn line can mean a restricted exhaust. There are some really good videos on Youtube showing how to analyze secondary ignition patterns. someone with a scope could probably find your problem in 15 minutes.