I bought a 1986 XT which had been sitting since 2001 with old rusty gas, the fuel system needed much repair, this is how I did it, and how you can too.
The metal "fins" inside my tank lightly rusted. I found this out after I replaced the fuel tank, and cut open my old one. The fuel pickup "sock" wasn't clogged at all in the old tank. I could have cleaned up the tank with some sort of solvent, there wasn't rust on the tank body itself. The rust/bad gas killed my fuel pump within 200 miles of driving, so don't drive on old gas. I replaced the fuel tank and filter and pump, drove some more, then the fuel pressure regulator stuck closed (due to rust/crappy gas) which caused high fuel pressure, stalling of the car.
My fuel filter was orange on the inside, the car stalled, stumbled upon acceleration, and would cut out. My XT had not only old gas, but moisture in a not full tank.
This is what you should do when you buy an XT that has been sitting for a while with old gas.
Remove the fuel tank & drain it on it's side, use solvent to clean the inside of it. The tank is held on by 6-8 bolts, and you'll need to drop the rear differential to get the tank out as well, which is 2 17 or 19mm bolts; use your lug wrench and a cheater pipe on those. Use a 10mm 1/4'' socket on the fuel filler neck hose clamp.
It's an easy job, BUT, the old hose clamps will be rusty and hard to turn by screwdriver, so just cut them and install new stainless ones; or you'll waste hours with them, like I did! If you don't drop the tank you won't get all the bad rusty gas out, there was a few quarts of the crappiest gas ever in there, that came out of the tank when I drained mine it on it's side, you can't get it out by removing hoses. That old gas/rust will wreck your fuel pump, it has to go before your pump does.
Then after the tank is cleaned out, you should splice in a clear fuel filter between the tank and fuel pump; it'll catch any residual junk and let you know what's going on in your tank! Only a few bucks. Your fuel pump is a bosch design, it can be cleaned out by reversing voltage & running it backwards, on diesel, AFAIK. Correct me if I'm wrong. This filter is the kind you're looking for if you want to put this before the fuel pump, a clear inline one, on the suction side of your fuel pump, the larger hose.
Also, remove the fuel pressure regulator and clean it (it's on the return line in the engine bay, has 2 fuel line connections, a vacuum hose) because in my case, it stuck closed and caused lots of problems. When I removed mine, pretty much solid rust came out of the inlet side. Mine was so bad I had to buy a new one. It seemed rust collected before that regulator and stuck it closed.
You can also blow out your fuel and return lines with compressed air. Remember if you're blowing into the tank to take off the gas cap or you'll have a nice balloon for a gas tank.
I did all of this, all the symptoms like hesitation went away with a tank of regular gas and a good heavy dose of fuel injector cleaner, within 40 miles on the highway. Now my 86 xt runs great.
Good luck, and don't rule out your gas tank as rusted out like I did; I learned this after taking a cut off wheel to my old one.