Ford Transit Custom 2016 – Starts bad – P008A Pressure in low-pressure fuel system too low

Hello, I have some problems with my Ford Transit Custom 2016 130 hp diesel. After longer service life the box starts very badly, it takes longer. If you turn the ignition key and wait before starting it (Glühspirale), it’s a bit better. Or that’s just imagination. With Forscan read out the following: Code: P008A – Pressure in low-pressure fuel system too low Further error symptoms (:21: – Signal amplitude is lower than the minimum status (-28): – Previously set DTC – Not available at the time of request – malfunction indicator lamp is OFF for this DTC images: 2x live scan from fuel pressure / live scan, engine off and off How would you first proceed? Thanks for the help.