Good evening, I recently purchased a 91 xj with 147,800 for 150 bucks yes 150.... It's runs like a champ up till this week when it's shifts to 4th it revs up and then shifts... I been doing some research, and worked aat a jeep dealer ship for 2 years it's came to the conclusion of tps, but I also might think the tranny might be going out... Which isn't to bad considering I bought it for only 150 bucks... But I wanted to get some opinions before I go and get prices for a tranny you know. Tomorrow I'm getting a new tps and seeing if that clears it up, it's only 40 at parts store. Other then that the guy that sold it to me ripped himself off. It's a 91 xj limited awesome jeep for super awesome price.. Anyone please help me out.. My number is 9043284563 to let me kno asap