Land Rover won't start

On this vehicle which hasn't been driven in a few years but started every few
weeks untill recently , after jumping it cranks but won't fire up. Sprayed
starting fluid in breather intake twice and it fires but no start so assuming it's
fuel problem. I have checked relay and power to relay , checked fuse on fuse
box to fuel , pushed down on inertia switch to reset , but no start and cranks
over well.
My question is : Can I be pretty sure it's the fuel pump ?  It always started up
before. I have to add that the fuel gauge reads between one half and one
quarter but , the vehicle is on a good nose - up incline.  Not sure if that can
affect the fuel level gas flow  I thought about getting into the fuel pump and
checking the power from the wires with key on. Also , no fuel pump sound.
Any ideas ?
                                                   Richard , in NM