One thing taht may be3 "effecting the cleaning" is a water valve that's got sediment in it and prevents it from filling with the correct water pressure it was designed for. Also, the food grinder may be broken or the filter isn't cleaning itself. Otherwise, those are EXCELLENT dishwashers. Based on the old Whirlpool PowerClean wash system, one of the absolute best cleaning designs in the history of recent dishwashers. Also, eitheer spray arm may not be rotating well. And the spray arm below the upper rack may not getting a good seal at the back of the tub to fill the spray arm properly. May we see more pictures?