Hello i have a bmn 170pd, doing some pressure tests as got an underboost. The lift pump gives out 1.4 litres per min and will go to just over 10psi once blocked off, the tandem pump will idle around 50psi and go to 150+ when you dab the throttle.
Now once the fuel pump is off there is no pressure left in the lines unless i clamp the return line before the filter, should there be some?
Now once the fuel pump is off there is no pressure left in the lines unless i clamp the return line before the filter, should there be some?
