I can't see how a bad TPS would make the idle speed hang up. All the throttle and cruise actions are mechanical as opposed to electrical (at least at the throttle body). Does the idle speed not return if the truck isn't driving? If so, rev the engine up and watch the position of the throttle where the cables attach to the throttle body, if it returns to the idle position but the engine is still idling fast then I would suspect the IAC, to verify that this is the problem, pinch off one of the hoses that goes from the intake pipe to the IAC (they make special pliers but a vice grip and a couple of pieces of wood will work in a pinch (pun intended)). If after pinching off the hose. start the engine and rev it up. If it returns to idle immediately, then the problem lies in the IAC system. Have you cleaned the IAC valve? They can get gummed up.