I am trying to find the problem with the vac droping to zero at times. While looking around I found that the valve I mentioned lowered the system vac from 17-18 to 13-15. If I unplug the input (and cap) to the valve and watch the vac, it goes up almost 5". I dont know if thats normal. The output side of the valve doesnt have any leaks so I believe the valve is causing the drop. It seems like alot of drop at idle.

I have replace the check valve in the pump and fixed many small leaks. I am leaning towards the valve inside the pump but found this oddity while looking around.