It'll crank, but it won't start

1991 Cavalier, 198,000 miles. On the way home from work it simply died. Had it towed home. Changed the fuel filter and check the fuel pump. All worked fine. Went to the auto parts store after discovering there was no spark. Paid $70 for a new ignition module and had the ignition coils tested. Put it all back together. Still no spark. What's next? The car isn't worth a tow to the dealer. Any help will be appreciated.