The dishes on the top rack are filthy, bottom rack cleans great.
I have cleaned the dishwasher, checked for food pieces, but the top rack stays very dirty, even if the bottom rack is close to empty. How do I get the water up there again? The dishes on the bottom come out great.
Check your upper spray arm for clogged holes and/or not raising up from the center if it does. Also, make sure you don't block it with a pot.
Try using a strong piece of wire (heavy duty paperclip or coat hanger) to make a hook to grab to post to pull it up or use it to clean out the holes. If you can take it apart you can try soaking the parts in 'Lime Away' to clean off the mineral build up if you have hard water.