If your dishwaser is leaving food particles and a slime all over your dishes try these steps:
Start with the simple checks listed below. Notice that the first item is to check the water fill level– this is the most common cause for poor cleaning in your dishwasher.
Check water level when the fill cycle has completed. Should be just under the heating element. If not, you may need to replace the water inlet valve.
Check the water temperature. Should be 125 to 140°F.
Check pump re-circulation. Listen: does it sound like it’s spraying the water around with enough pressure?
Check the spray arm and pump cover for splits or leaks.
Check to make sure dishwasher is draining after each cycle. There should only be a little water in the bottom of the tub.
Make sure the dishes are loaded properly, or dishwasher is not overloaded.
Possibly try a different detergent . Some liquid-gels will bubble and a pump cannot pump bubbles. Make sure the detergent is fresh.
This informatiom is from: fixitnow.com
When I had a dishwasher, I would run white veinegar through it once a month with no dishes in it; 3 to 4 cups poured into the bottom of the dishwasher, and then with each load I used white vinegar as a rinse aid rather than the rinse aids you buy. Always helped!
Hope something helps!