webb06
Active member
2015 6.7 cummins
62,000 miles
Truck came in with low rail pressure and would barely move under its own power. Rail pressure was 3500ish psi. Any kind of throttle input and rail pressure would drop below 1000 psi and truck would stumble and barely stay running.
Checked fuel filters and there was a terrible amount of water in them. Changed both filters and removed the tank and cleaned it out. No metal in rail or lines. No change in the way the truck runs.
Replaced FCA. Now as soon as truck is started rail pressure ramps up over 28,000 psi. Tried another FCA off of a running truck. No change.
Sometimes the rail pressure will drop below 12,000 psi kind of like the ecm is trying to protect the system. Commanded pressure when rail is extremely high is around 9000 psi. When rail pressure is 12,000 psi commanded rail 22,000 psi.
Swapped a different cp3 onto the truck. No change. Removed injectors and had them tested. All tested okay. Checked low pressure supply. 10-12 psi. Unhooked returns individually, no change. Fuel rail relief valve only opens when FCA is unplugged.
Only code that comes up is P0088 high rail pressure. Checked voltage coming to FCA connector. 3.5v unplugged with key on. Compared to another truck and it is the same voltage. Replaced FCA connector because I saw many cases online of it fixing similar issues.
Any help or input is appreciated. Hoping to swap ecm with another truck soon. That’s about the only thing I haven’t tried I feel like.
Sent from my iPhone using Tapatalk
62,000 miles
Truck came in with low rail pressure and would barely move under its own power. Rail pressure was 3500ish psi. Any kind of throttle input and rail pressure would drop below 1000 psi and truck would stumble and barely stay running.
Checked fuel filters and there was a terrible amount of water in them. Changed both filters and removed the tank and cleaned it out. No metal in rail or lines. No change in the way the truck runs.
Replaced FCA. Now as soon as truck is started rail pressure ramps up over 28,000 psi. Tried another FCA off of a running truck. No change.
Sometimes the rail pressure will drop below 12,000 psi kind of like the ecm is trying to protect the system. Commanded pressure when rail is extremely high is around 9000 psi. When rail pressure is 12,000 psi commanded rail 22,000 psi.
Swapped a different cp3 onto the truck. No change. Removed injectors and had them tested. All tested okay. Checked low pressure supply. 10-12 psi. Unhooked returns individually, no change. Fuel rail relief valve only opens when FCA is unplugged.
Only code that comes up is P0088 high rail pressure. Checked voltage coming to FCA connector. 3.5v unplugged with key on. Compared to another truck and it is the same voltage. Replaced FCA connector because I saw many cases online of it fixing similar issues.
Any help or input is appreciated. Hoping to swap ecm with another truck soon. That’s about the only thing I haven’t tried I feel like.
Sent from my iPhone using Tapatalk