Cat c12 fuel problem

okay so I have a c12 with a fuel problem, it runs rough/sounds like it has a miss almost and is low on power, the fuel filter and water separator are new. I’ve replaced the filter housing as well so it rules out the regulator in there, the transfer pump has also been replaced and the fuel is clean, I’m stumped. Am I missing something here, is there another check valve somewhere on the head/fuel rail. Also at idle and high idle which is 1500 rpms I’m getting 40-no more than 50 psi of fuel pressure and it moves around in that range a lot like jumps around, and when I hear the engine slightly bog down is when it hits 40, finally there are no codes of any sort in CAT ET and all the injector solenoids tested out good and I also did a cylinder cutout test, any help would be appreciated.

 

Do you have a fuel restriction gauge?

 

No?¿

 

From what I've heard about C12 CAT engines is they can go bad in many ways. Rebuild them and 1 week later they are scrap.
The worst CAT engine ever, and replace it with a C13, I hear often.

 

Pretty bad advice.

 

To make fuel pressure, you need fuel. Need to plumb in a sight glass to see if you are sucking air and how old are your suction and return hoses? Could have a collapsing or restricted hose.

 

More truck stop coffee counter B.S.!

 

I'm with the sucking air or restriction idea as well.

 

Is C12, or C13 the problem child? I may have gotten it backwards.
Or it's just bad advice on all accounts, and C12, and C13 are both reliable engines?

 

Idk where

idk where u get ur info from but c12s are one of the best engines, we have one in our fleet that has been running since 2009 after a rebuild with no problems at all since