When the TPS loses power or quits working the Transmission goes into a "Limp Mode" of sorts. It basically goes fully manual. The transmission will be in whatever gear is selected by the shifter. So, when you put it in OD and try to go, it feels likeit's slipping and not wanting to move because you are in effect trying to take off from a dead stop in 4th, OD or HIGH gear. Try this, start out in 1-2 and then manually go trough your gears. I bet it will drive just fine if you haven't fried something from trying to get it to move from a stop in high gear so many times....or if you haven't overfilled it by dumping in those 2 quarts of tranny fluid without first checking the level.
Brian "Buck" Buchanan, U.S. Navy Chief Petty Officer (RETIRED) - 87 XJ Laredo, Ol' Red - 8.5" Rusty's Offroad/Rough Country lift, D30 trussed and D44 high clearance shock mounts, 4.56's, Aussies, Chromos and Disc Brakes front and rear, JCR Offroad Belly Skid Plate and Stage 2 Rock Sliders, Off Road Fab Winch Bumper and Quarter panel Guards, Liberal Front Wheel Well trimming and Rear Wheel Well Cut N Fold, 35" Goodyear MTR with Kevlars, Cobra CB and AW4 First Gear Lock Crawl switch, SYE, Stock XJ driveshafts front and rear and Milemarker SEC8000 Winch.
91 XJ Sport (Old Gray Jeep) - Layed to Rest (04-01-13)
87 XJ Laredo (Ole Red) - (My Jeep)
87 XJ Base (The Boys Jeep)
96 XJ Country (The Daughters Jeep)
08 Dodge Charger R/T (The Wifes Ride)
04 Silverado 2500HD Duramax/Allison (tow rig)