MY 91 Land Cruiser loses power when going uphill.......why would this
happen?? Anyone experiencing the same problem??

my 92 does the same thing. once it wouldnt even make it up the hill while i was towing a boat. i opened the gas cap and the air rushed into the tank. then it made it up the hill.

now i live where its flat, no hills, but it still runs kinda shitty sometimes, like it has a mind of its own, good one day bad the next.

You probably need to blow out your gas cap as it sounds like the vent is plugged and there is no air getting into the tank. Try cleaning it out, if that doesn't work replace the gas cap. Should fix your problem.