You will find some excellent free ignition troubleshooting information at this website: cdielectronics.com. Better than the factory manual that year. Statistically, the powerpack if the most frequently failed item. Certainly, I would not recommend replacement based purely on a statistical basis. Since all ignition components are really expensive now, it will pay you to invest some troubleshooting time into checking out all the components, esp the timer base and the stator- first. Eliminating them from consideration goes a long way towards pointing to the pack as the culprit.