purchased my xj last december, drove it a couple months motor wound up given up. its a 89 xj auto, i got a great deal on a 94 H.O. motor so yanked the motor, left all H.O. stuff on the motor except for the alternator cause i didnt get it with the motor. H.O. intake and exhaust, installed all my sensors, made an adapter for the T.P.S. all seems well except it has a rough idle. i noticed i can drive it around town up hills down hills back around town everything is fine, except for the rough idle. then out of no where it starts to shudder while driving, bucking almost. almost all sensors are new except for the TPS which appears to be pretty new. i tried adjusting the tps but seems like nothing happens the voltage dont really change when i move the little arm. could the tps be my problem? seems like the shift points are slightly off it holds a gear a little longer then it used it. my tranny line to the radiator is pinched pretty good like almost closed is it possible the tranny is sucking dry? the motor would just rev like it was in neutral though wouldnt it? this actually reminds me of a person trying to drive a manual transmission, to high of a gear for my speed. maybe the torque converter was locked up load? i was going up hill everytime it has happened so far. any help would be greatly appreciated im seriously going insane. this is my first jeep and so far its been a bad experience everything has gone bad already and it only has 148k on it.