Replace the coil and coil wire or, even, a whole set of plug
wires. What you are looking at is corrosion (oxidation)
that results in the presence of a bad high voltage
connection over time. You should be able to get a
serviceable aftermarket coil fairly cheap. The wire should
be under $5. Keep in mind this same corrosion is probably
present on the distributor cap terminals and towers. It is
a result of inadequate dielectric grease. Generous
application of dielectric grease on all secondary ignition
connections will usually prevent this from happening in the
future. That's why I buy the stuff in the large tubes.
Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here.
All logos and trade names are the property of their respective owners.