1993 Mercury Sable Car won't start

If you have fuel, and the engine will not start, then the problem is most likely an ignition problem. Check for spark at the spark plug wires. Us an inexpensive spark tester.

There are many things that can cause spark problems. Among them:

Ignition module.
Sensor inside the distributor (PIP sensor)
Coil
Wires (primary) broken, chafed, or shorted.
Connectors not fully engaged or terminals loose.
Distributor not turning. This is usually caused by a mechanical problem with the drive gear.

These are some things to start checking. Keep in mind that I cannot fix your car over the internet. You must be my eyes, ears, and hands. I can only supply the knowledge to help you in diagnosis and repair.