Join Date: Mar 2002
Location: Austin, TX, USA
Coils don't very often go bad with a couple of exceptions. First, if the ballast resistor or resistor wire is missing they will over heat. Second, if the coil is laying on it's side, the cooling oil won't cover the windings and can allow it to burn up internally.
First off, make sure you dont' have + and - reversed. To test the coil, you need to take a resistance measurement. Measure from the high voltage lead to the - terminal. I'll take a measurement for you later to compare, but for now I'll guess you'll see a few hundred ohms. Next, measure from the + terminal to the - terminal. I'm guessing about 15 ohms.
Other things that can cause poor ignition are bad points or improper dwell, grease on the points from an over-greased dist. shaft or rubbing block will do it. Also, a bad condensor will make it run poorly - especially at hiway speed or part throttle cruising. If you suspect the condensor, take it off for and see if the misfire diminishes.
68 Coupe, 350 w/ Edelbrock Performer RPM heads, cam, intake, 700R4, Dave's small body HEI