92 Bonnie - Crank Sensor or Fuel Pump??

I have a 92 Bonneville with 160k miles that my dad drives. One day it just stalled while he was driving. No loss of power, no sputter, just "off". It would crank and crank and crank forever but will not fire. If you let it sit for about 30 minutes- 1 hour it will start right back up like nothing was ever wrong. Check Engine light is NOT illuminated. Runs fantastic all of the time otherwise (gotta love the diehard 3.8!)

I rented an Actron handheld scan tool. I got a code for "RPM sensor fault". Of course, that meant nothing to me. I suspected the crank sensor from the beginning but the scan tool didnt specifically tell me anything. A few questions

1.) Where is the crank sensor located?
2.) Is there only one?
3.) Does this sound like a typical 3.8l crank sensor failure?
4.) How hard is it to replace one?

Any help is appreciated. My dad is in a very hard spot right now and needs the car to get to and from the doctor.

This sounds like a CPS issue. The CPS will often go bad and not throw a code. It is located behind the harmonic balancer on the front of the engine. It is not hard to replace but you will need an impact wrench capable of at least 150 foot pounds. Once you replace it you will need to run the engine to the rev limiter a couple of times so that he PCM calibrates itself to the sensor.