2002 Ford Explorer

I have a 2002 ford Explorer mechanic special. Truck runs but doesn't roll well. It has a new spark plug sillinoid,brand new upper control arms, thermostat, water pump,tie rods,rear brakes, Probably needs rear calipers and rotors. I've come to the understanding that I cannot figure out what's wrong and I've invested way too much money into the last 4 months and still can't roll on. So if you want it for parts, I don't have the convenience of doing that at my residence but for 1200 bucks and a lift out of here it's yours. Has 2 keys,air works in the front. It's got 230,000 miles on it but it was well maintained. I've been working on it for a while so I need to clean out the cab.