I'm still trying to straighten out the ignition on the 1800ES. The car is box stock.

Symptom: Engine starts but within a minute, or less, the ignition starts to miss. It quickly gets worse and worse until it dies. I've attached a timing light to both an individual plug wire and the coil hot lead and witnessed spark deterioration.

So far: I've replaced plugs, points, condenser, rotor, and cap. The plug wires are old but they are the old copper wire core ones and the terminals appear intact, so I'm not suspect of them at the moment. I've tried two different OLD coils. At the moment the coil is drawing my attention. In 50 years of driving I've never had a car that the coil went bad. Oh, I have NOT yet monitored voltage from the ignition switch/fuse box to see if voltage is dropping in conjunction with the missing, from something like a corroded fuse.

Questions: What resistance tests can I run on the coil to indicate a problem? Can a coil go bad over time just from old age (shelf life)? Are there any other failure points I should be looking at?

Thanks once again.