Fuel pressure regulator vacuum hose

[Coefficient]

Can I just check that this is not supposed to be connected to the plenum? It just dangles free. I can see where it is supposed to go on a standard rover v8 but the stepper motor seems to be there instead. Could be wrong though. Cheers

[Coefficient]

Never mind, I found the nipple. Does that hose subtly change the fuel pressure according to plenum vacuum?

[KevtheRev]

Yes, regulates fuel pressure to around 2bar at high manifold vac & 2.5bar at low vac.