Before you blow money at cheap no brand/bad brand parts at autozone (they do have some oem things but don't think a coil would be one, could be wrong.) I would spray test it first. Open garrage at night. Pull in car. Pop hood prop, dim lights motor still running. Spray coil and wire area once to detirmine where it is arching. It may be arching from a wire, or the coil. Even the rotor inside cap can arc I believe. You can open the distributor cap now and inspect the rotor. If it's burned, she's done.