1991 xj 4.0l 150000 khm.I wash the engine with hot water,in car laundry,after that,i work't once the swich comfort-power on a hill,and after change gears at 4500 rpm only.If anyone have any information,thank you in advance.Alex Amanatidis from Greece

 

Hmmm i dont think your going to get any usefull replies since we cant really understand what your saying (no offense)........

 

It might be the TPS (throttle position sensor).Its mounted to the throttle body and can cause erratic shifting if it gets too wet.