1984 nissan 300zx nospark

almost at the end of my 300zx. A 1984 300zx turbo. If anyone can help graetly appreciated. Drove the car about 3 times total of 200 miles. loved it but now there is no spark. After a tow, diagnostic charge, and new coild it started once. Now there is no power to the coil. Tried to hook coil up direct and still no spark. What actually controls the pulse? Car ran fine, just shut off and never started again. Thanks for any input because i would love to start modifying this car, but not untill it is running again.