Just started one day. On the highwY going up a hill check engine light came on and threw my scanner on it. Said low rail pressure and went into limp mode...reset codes. And I could watch the rail pressure go from 20000 and then going up hill it would drop to like 2000 PSI But so far I have replaced all the seals in the fuel filter housing primer housing and added a lift pump and problem is still there I try power breaking in my driveway and the fuel pressure goes up and then drops down to like 2000 . Is there some sensor that could be going bad that causes this but also my fuel pressure regulator I have replaced with a race valve from evil energy it's just dead headed Now. I don't know what else to don't know what else to do I am not getting any air to the CP3 Pump. Any help would be appreciated I'm at a loss I need the truck this week
2003 lb7 rail pressure drops under load
- Thread starter Tim24fan18
- Start date
based on your original post, it sounds like you put a "race valve" in the fuel pressure relief location already, correct?
going from 20k psi to 2k psi doesnt really add up to a CP3 or injectors, generally you see a slow taper off or actual rail just wont go above a certain point (IE: you command 25k but actual only hits 20k).
Did this problem start not long after the race valve was put in? have you checked your oil for fuel in it? can you command rail with your scan tool and have it drop psi at at specific psi every time?