Land Rover Repair: Discovery II engine dies

Question
1999 Discovery II
Engine dies after running for short period of time. Engine light is on and car will start. If engine light is off engine just cranks over but will not start. Engine running with engine light on when it engine light goes off engine dies. It has new crankshaft sensor and new MAF sensor. Have bypassed fuel relay and no change. Engine is getting fuel. I have held it at 2000 rpm and will still die unexpectedly. Same thing at idle. Thanks for info you have.

Answer
This statement:  If engine light is off engine just cranks over but will not start is consistent with a cam sensor thats intermittently failing.

This statement: Engine light is on and car will start means there are codes stored.  What are they and what do they suggest?

In your situation you really need a quality scan tool with live data display so you can see what the various readings are.  Without that it's a really costly guessing game