914 Fuel Pump Indicator

From what I know, the usual way to monitor a 914 is to install a fuel pressure sensor on the outlet of the fuel pressure regulator. Now the thing is that the regulator takes the reference from the airbox pressure normal fuel pressure is 0.25 BAR (3.63 PSI or 7.41”) above airbox pressure. So either the fuel pressure sensor is a differential type airbox/fuel manifold or you get some indication of pressure, but you have to read and understand it in reference with the manifold air pressure.

More details here, chapters 14 and 15.