Sounds like you might be a candidate for the valve body mod where they overbore you a new pilot hole and insert an oversized ball valve kit. Could also be that you just have a tired solenoid. They can and do happen from time to time. I would ask about the possibility of either one being the fix needed to keep you rolling before you opt for a rebuild. And boy howdy, do they like to push a rebuild on you. Good and much luck to you my friend!