Trying to solve a LPFP issue...duty is 91.8% all of the time.

[Roh Echt]

I've been trying to help another who keeps getting a P310B fault...their log data shows LPFP duty always at 91.8% and low pressure actual at just over 3 bar.
Also, it is tuned stage 2+ but the HPFP specified takes time in the data to reach 109.9 bar at full throttle angle...but his upgraded HPFP is producing an actual pressure of over 140 bar.

He has replaced the G410, LPFP, electric fuel pump control module, and fuel filter (6.6 bar).
Could this have been an electrical issue all along? He says he doesn't visually see anything wrong and I have suggested at this point to have someone with electrical skilll do some probing.

 

[DrPeter]

Hello,

It is difficult to give you the exact information you need to help fix the vehicle in question. An Auto-Scan would be helpful or at least can you provide a make, model, year, engine code, etc ??

Here is a Ross-Tech wiki page that in general should be helpful when you have a the fault code:
P310B - Low Pressure Fuel regulation: Fuel Pressure Outside Specification

You can find some really good information in the Official Factory Repair Information.

Thanks, hope this helps,

drpeter