1993 Nissan Altima no firing

Did you have a check engine light come on or has flashed prior to this problem and when was your last tune-up?

Cranks but no start condition:

Fuel and Spark:
Get a helper disconnect a sparkplug wire or 2 and ground it to the engine at least 3/16 away from ground -have helper crank engine over-do you have a snapping blue spark? If so-you have a fuel related problem, check the fuel pressure to rule out the fuel filter/fuel pump/pressure regulator and listen to the injector/s are they pulsing or hook up a noid light. No snapping blue spark continue to troubleshoot the ignition system-power input to the coil/coil packs, coil's resistances, distributor pick-up coil, ignition control module, cam and crank sensors and computer Note: If it doesn't apply disregard it.

Also it doesnt have a crank sensor -It does have one its called crank angle sensor in the distributor

You need to perform some testing here such as the coil and distributor pick-up coil