My dishwasher started washing poorly a few months ago. I replaced the old pump with a complete new assembly, including solenoid (it is nice and quiet), but the problems intermittently persist. What it sounds like is that the water fills the tank, but the drain doesn't shut off, such that I get a "dry" wash. If I turn the knob all the way around to start the fill again, then it's OK. Is it possible that the new pump and solenoid is defective? Is there any other reason for the drain to "stick" open? I've checked the hose and garbage disposal inlet for blockage.