Take the hose off the inlet valve & put the end in to the sink. Turn tap on full & check that the water flow is strong. If water pressure from tap is good & you have installed new inlet valves & connected the wires up correctly then the only other thing it can be is a problem with the control module which supplies the power to the valve. If it does not give the full 12 volts it will not open fully. The only way to test & be sure is with a test meter. Then it would mean a new control board.
Lincoln Appliance NZ, January 2010