I'm a little late on this thread. Check the ignition control module. Sometimes the contacts, especially if it's an old module spread out or expand and don't make contact with the harness wiring.
Had the same issue with a 1997 Buick Regal LS ; engine cranking and not starting. No spark was going to the coil packs. Trouble shooting the wiring at the module, pushing the harness into the connector
and was able to get the engine to fire up. Put a new module on. That original module was 22 years old.
Also could be the on board computer too. Is the fuel pump running continuosly? If so, computer is going bad.