how do you determine if it's a crankshaft sensor that's making it not fire

Replace distributor cap and plugs and wires and still won't start

CKP is one of the only sensors that cause a NO start. It can be tested but most people don't have a PC based oscilloscope forget the multi meter testing to much time and work if the car has 80,000miles on the Crankshaft Position Sensor.. change it!

Try changing the cam sensor. It was causing mine to not start. Cheap part easy to install. Same with crankshaft position sensor and mapping sensor.

The small fuse under Hood that says start/fuel is most likely blown replace it and it should start right up. Its that simple. Probably too late