Need help with GE Dishwasher

We have a GE Dishwasher GSD4620Z02BB. The water is not pumping out. I have replaced the pump and the gate valve plus the piston and nut. The motor/pump seems to be working but how do I know this for sure. Please email me at drprntg@windstream.net. Also could there be a problem with the cycle timer not opening something that causes the water to pump out?
Darwin Alexander