The hose from the manifold of a 3.9 injection, is only to warm the throttle blade and is not necessary.
The hose should originate at the top of the RH tank of the radiator. There should be 2 hose stubs on there,1 to the header tank and one to the throttle blade.
Why on earth has someone monkeyed around with the hoses?????
As a 3.9 it should have 2 steel heater hoses along the RH top of the RH rocker cover, with a filler nipple in one. This is the highest point of the engine and should be where the final top up and bleed is done.
Has the car got the correct lower radiator hose with a T hose to the bottom of the header/overflow tank? If so I do not see any need for other hoses.
If it is a "cobble up" of a 3.5 manifold, you should face the car steeply up hill when filling into the filler hole on the RH of the radiator.
You are really feeding us piecemeal information here.
How about some photos of what you mean and a FULL description of the setup on the car.
You should have absolutely no airlock problems on a standard 3.9, as Land Rover changed several thingsfrom the 3.5 eg the heater hoses precisely to stop airlock problems.
Help us help you.
Regards Philip A

