Cummins ISX fuel pressure code

High everyone. Need some help. My truck tossed a code at me the other day. It was 128 94 0 which is fuel pressure too high? Now the truck is running but at half power. Other than power loss, and the high pressure fuel code I notice no difference. The power loss is a lot, about half. I can't figure out what would cause a high pressure code? And why a power loss with high pressure? Low pressure understandably, but high pressure? What would cause this and how can I fix it ?

 

I posted the code and yes it is an active code, it happens every time I start the truck, then does not happen again until it is started again. One code each time I start it. I have 6 instances now since it happened. That's 6 days work, start in the morning, new high fuel pressure code. But it makes the engine run at half power. The code again is 128 94 0, 128= engine, 94 fuel system, 0 = high pressure. With the power loss I expected the "0" to be a 1 instead meaning low fuel pressure, but its a "0" meaning high pressure problem. Another member on another site has suggested the fuel pressure sensor, or the fuel pressure regulator. Seems probable. I'm going to toss these parts at it see if it fixes the issue. Now if I could only identify were they are. I'm having trouble signing up to quickserv. There site is not working correctly.

 

ESN=79117975

 

I finally got into quickserve. Found the sensor, but not the regulator. Sensor was right under the 4 solenoids for timing and metering. I think the regulator might be in between the solenoids, but not sure. Drawing is hard to read its so busy. Looks like a fat bolt in the middle below the shut off solenoid?? I'll get the sensor today, maybe the regulator if I find it.

 

that code is straight off the engine cpu on the truck. The dash computer is like a scanner and you can pull all the codes from the modules and clear them etc. The code is 3 numbers, MID128 PID94 FMI 0, straight off the engine cpu. Cummins codes says that means fuel pressure too high.

 

I finally got into quickserv. It still won't let me login, but it remembered me from the temp login and let me in. Hopefully it keeps me logged in since the sign in fails me. Got the pump drawing and found two regulators and the sensor. So off to the parts store for some junk to toss at this motor. lol. Cross your fingers.

 

I don't have access to insight. I have autoenginuity but it uses a generic ob2 port, my truck has this big ### round interface plug. I think its specific to volvo. They want 150 bucks just to scan the computer and tell me the code. I found the full list of codes like my truck on the cummins site, but as you said, quickserv doesn't use that type of code. Wonder why cummins made those codes if they are of no use.