Really need help fuel rail pressure

[Cwmartinjr]

I really need help with this issue. I am showing a spn code 1239 stating fuel leak but when plugged in to a computer it states fuel rail pressure loss. I don't belive it's an injector because of no fuel in the oil.i have replaced the high relief value that changed nothing. Took truck to the shop they said high pressure fuel pump and suppose to have diagnose the problem and guess what still doing the same thing. I have lost around 100hp 6 percent boost and my pyrometer is about 300 degrees off where she should be while pulling. I have a 2014 Cummings isx 15 litter 550hp 2250 torque.

[Rawze]

How many miles on truck and enigne?

Here are some interesting reading on the fuel pump and 2350 fuel system...

The Cm2250 and CM2350 engines have the fuel pump of complete engine destruction ... it is a well known issue with that engine and it is nothing to play around with. Here is what happens when you don't change the guts of the fuel pump every 400k miles or so...
http://rawze.com/forums/showthread.php?t...9#pid15389

--- that being out of the way...


your statement here...

(09-11-2019 )Cwmartinjr Wrote:  ...
I don't belive it's an injector because of no fuel in the oil
....

Injectors on the 2250 and 2350 will usually leak internally (back to the fuel return system) and back to the tank, not into the oil. Assuming that it could only leak fuel into the oil when one goes bad is absolutely incorrect. The only way to properly check them is via a pop-tester (mentioned here: http://rawze.com/forums/showthread.php?t...52#pid9552 ) or by blocking lines off until you find it.


it can also be the pump. They have been known to fail and become leaky internally too.

[Cwmartinjr]

Thank very much for your post . I will look at the links you sent. Thank you again