Low fuel rail pressure

[scott441974]

Hello, I'm having an issue with one of my trucks. Truck will lose power then it will eventually come back. It logs a code of low fuel pressure when it loses power. We changed all the fuel filters, it didn't help. This has been on and off for several months. Anyone know what this could be or what I need to check. Anything would be helpful. Thanks

[Bengy88]

Which engine we working with here? It could be anything from a cracked pickup tube to an injector. If it’s a 2250, 2350, or x15 has the fuel pump head been pulled and the rollers checked if it’s over 450k miles?

[scott441974]

(02-13-2023 )Bengy88 Wrote:  Which engine we working with here? It could be anything from a cracked pickup tube to an injector. If it’s a 2250, 2350, or x15 has the fuel pump head been pulled and the rollers checked if it’s over 450k miles?

I'm sorry, Its an X15. I had peterbilt send their mobile mechanic down to check it after I read about the roller issues. But he never pulled the head off and checked them. I'm guessing that's the 1st thing I need to do.

[scott441974]

(02-13-2023 )Bengy88 Wrote:  Which engine we working with here? It could be anything from a cracked pickup tube to an injector. If it’s a 2250, 2350, or x15 has the fuel pump head been pulled and the rollers checked if it’s over 450k miles?

I told you wrong. This one is a 2350.

[Bengy88]

That’s the first thing I would do. There is like a 400k service interval on the fuel pump. If that checks good then an injector leak down test would be next. If you jump on YouTube rawze has some good videos on checking pretty much your entire fuel system

[amermextrucker]

If it's a CM2350 on mine I had code 0559 , turned out the issue was the check valves in the fuel pump head went bad, when doing a leak down test pressure couldnt build to commanded pressure, but like I said I had the code of death on mine.

[Rawze]

(02-13-2023 )Bengy88 Wrote:  That’s the first thing I would do. There is like a 400k service interval on the fuel pump. If that checks good then an injector leak down test would be next. If you jump on YouTube rawze has some good videos on checking pretty much your entire fuel system

here is more info on doing that leak test ...

ref: http://rawze.com/forums/showthread.php?t...2#pid69262

what is the starting pressure.. and then the pressure after one minute?.

[SquareOne]

(02-13-2023 )amermextrucker Wrote:  If it's a CM2350 on mine I had code 0559 , turned out the issue was the check valves in the fuel pump head went bad, when doing a leak down test pressure couldnt build to commanded pressure, but like I said I had the code of death on mine.

I had this issue on my CM2350 last year, although I didn't have the code or any 'noticeable' changes in how the engine performed. Only indications were a slight fuel leak around the torx plug on top the high press fuel pump head, and a stumble when performing the fuel pressure test with Insite.

The solution was to replace the high pressure fuel pump head assembly (will come with the barrels and plungers pre installed). The head is not a serviceable part once compromised.