Dishwasher Problem

I recently purchased several parts from you including the upper dish rack sprayarm assembly. I also replaced the lower sprayarm seals.
I have been having trouble with the dishes getting clean. The upper rack that has all of the plastic and glass glasses usually look real foggy and unwashed. After replacing the above parts it still appears that some of the glasses are unclean. Could it be that the pump or the pressure switch is not working properly?