in my experience, crank sensors fail outright and i haven't SEEN stumbling and/or hard starts. possible, yes but not likely. usually it's running ok until the sensor heats up and the car stalls. cools off, starts fine.

in those cases, and yours, i hook my test lead up to my scope, close the hood to keep the heat in and watch while cranking or it's running. once it stalls, crank again and watch. testing for resistance won't work because you don't know the temp it fails at-if that's the case. and any voltage can pass through during an ohms test, but is it enough?

in your case, without testing anything, i would look at the ignition system. new and correct plugs-bosch or ngk copper only-no platinum. bosch oe style cap and rotor-no other brands. plug wires-not bosch gray silicone but beru or karlyn are fine. look at the coil, see any white-out on the outside? flashover burns from a failing coil-very common in that generation ignition setup due to too much resistance in the other ignition parts. all ok looking-then i test. scope the coil and look at the secondary kv. then scope the crank sensor.

leaking injectors and/or fuel distributor can also cause the same symptoms. but then, i can't see under your hood. the light here sucks. good luck, chuck.