[Dancake]

The FPR could test ok with the resistance check, but it won't tell you if there's a blockage or mechanical wear within the regulator. I've fitted hand primer pumps to a few engines over the years, mostly diesel Fords as they can be awkward to start after changing the fuel filter. They should be fitted to more engines in my opinion, as when needed their convenience can be a great time saver. You can place it on the supply line to the HP pump no problem.