I have a 1989 OMC, Ford V-8, 5.0 L 302, Cobra outdrive. Last year it was fine, now it's driving me nuts. Have no idea why it's not firing at plug. Many new parts, 12V at the coil, but still no spark. New parts coil, Seleniod, starter, distributor, condenser, points, plugs and plug wires, new...