LPFP Pressure Issue - Upgraded LPFP


Sep 26, 2019
E36 M3, E90 335 ST
I have the precision raceworks stage 3 kit installed. The LPFP pressure is at 72 psi but once the second pump is activated (via hobbs switch) the pressure rises to 85-87 and seems to stay there. It will go back down to 72 psi if I turn the car off and restart.

I did some searching regarding this but wondering if there is any new info about this. Some said that running at 85 psi is fine but it doesn't make sense to me. Shouldn't the hobbs switch deactivate the second pump when boost goes below 15 psi and lpfp pressure return to 72 psi?