How weak is that spark in the dead cylinder? You may have enough spark with all the stuff you replaced, but that cylinder could have a broken reed, or some dirt stuck in a reed keeping it from shutting completely; or low compression maybe due to a blown head-gasket.
You could have gotten a bad ignition part – you can try swapping condenser, coils, spark plugs between cylinders, but do it one at a time, so if the problem moves to the other cylinder, you will know which part is bad. It’s rare, but I have had bad condensers, coils, and spark plugs new out of the box. An ohm test on a coil will not tell you if the insulation is breaking down, bleeding the spark off to ground somewhere, like to the coil core.
Good Luck!
Dave
