been through it all and all seems fine. Replaced motor recently. Doesn't appear to have any internal wear in the head. Venturi assembly and all seem fine aswell. Cycles correctly and drains fine. Just after the fill cycle, it briefly creates a suction and thats it, probably a spoonful. This hard water stuff is getting old too!
My only thought is a small leak in the line or fitting that allows the filling to occur but isn't allowing enough suction for water, but I don't hear a leak.