why does my range rover p38 randomly stall and wont start again for ages on 1998 Land Rover Range Rover

the car can be drove for an hour or days without it stalling then suddenly with no warning it will stall usually when braking or slowing down at a junction also the fuel gauge doesn't always read the amount of fuel in the tank or when you think it is low it will suddenly go higher plz help its driving us mad

Fuel tank issue is most likely a corroded fuel ballast, i have the same issue and it is not worth the money to fix. Your other issue sound like a loose crankshaft position sensor or it is not connected all the way. It is located near the #8 Cylinder underneath.