Thinking about it, if it's a diesel with the mechanical fuel pump then it'll run without the crank sensor as it's timed mechanically. Just out of interest, does your tachometer work with the crank sensor unplugged?

Maybe it could be a PCM fault not outputting 5V to the sensors.

Do you get any voltage on the sense wires so the Grey/Black on the crank and Orange/White on the VSS? I'm just wondering if this 0.94V is coming from the sense side of the PCM, which is the only thing I can think of that would drop the voltage when disconnected, the 5V line is dead but picking up voltage from the sense lines.