Why after i changed pvc valve/crankcase my car won't start now

Hello, really can't explain why your vehicle will not start based on the current information. If the engine is not cranking, it is a starting system issue, starting with the battery. If the engine is cranking, you need to find out if you are missing spark, fuel, air or have an exhaust restriction. I recommend a local qualified technician have a look - check this link to find some local folks near you: http://repairpal.com/land+rover-within-10-miles-of-upland-california-91786