acceleration...

i also have a 2000 jeep grand Cherokee, i recently graduated from an automotive college and happened to throw my jeep on the lift one day... well i think part of the lag on acceleration is bad u-joint... and i also took my throttle body off and cleaned it up which is pretty tedious in itself... it seems that cleaning the throttle body helped, but you should also try changing your spark plugs....you should also check your air filter too as a restricted air filter will not let the air needed to the throttle body and will cause loss of power... hopefully some of this helps...