I just picked up a Discovery that has a no start problem. When the car is cold it will start and run for 3-5 minutes but then dies and will not restart for a hour or 2. From the research I have done on this site it seems my problem could be caused by the crankshaft position sensor. Is there any way to test it rather than just going out and purchasing a new one? Also is there any other things for me to check? Thank you in advance.

 

No way to test a CPS.
Just replace it, $70 at AutoZone.
3 o'clock position looking at the engine.

As for what else to check, read the top three threads on the top of the Disco page.
Read EVERYTHING.

 

Actually, if you have access to a "GOOD" scanner you can trouble shoot any sensor, including the crank sensor by selecting that sensor and reading the signals from it, then compare then to a good shop manuals specs.
For the crank sensor, you must read the signal while trying to crank over the engine and if I remember right it will show in volts from 1 to 5, I think.

 

Would a voltmeter do the trick?