This was exactly the problem with our Whirlpool dishwasher. I bought the sump and assy from sears parts website and boom it works again. Same issue where it would load with water and just sit for hours sometimes before it would drain but it never would run the cycle in between with the sprayer(s). Didn’t matter what cycle I placed. I tried unplugging it, plugging it back in and no dice. So thanks for the answe cause a $750 dishwasher we bought and I replaced the piece at $120 instead of buying another dishwasher!