One test you can make is to disconnect the dist. connector. Take the ECU end of that connector and tap the bare protruding terminal to ground with the key on. Each time you should get one "snap" spark. That will prove the coil/ box is working. Always cast a suspicious eye to the dist connector for dirt/ corrosion/ looseness, and have a look at the pickup/ reluctor for wobble, shaft wear, damage, rust. etc. Scare yourself up a .008" (inches not metric) feeler and check the reluctor to pickup gap You set it just like breaker points by adjusting the pickup with a set screw