I have a 1986 Corvette that has a miss and runs rich. In the process of elimination I have tested the coil, pickup coil is new, Cap and rotor new, MSD spark plug wirers test with in range. I hooked it up to a timing light and the spark is very erratic on every cylinder. Timing light is working correctly have tested it on another vehicle. I can not seem to figure this out!!!! Any help will be greatly appreciated.