LML falling on its face, losing all power at around 22-2300 rpm,

[kvw4x4]

this truck has been a project and now I need more help
if you keep the rpms below 2200-2300 rpm it will run fine, if you put it in park and rev it up it goes as high as you want without issue, but if you go over the 2200-2300 rpm range will driving it completely loses all power, the truck has complete egr delete, def delete,and cp3 conversion, tuning done by motor ops, we had this issues 2 weeks ago and motor ops had me unplug the throttle valve, it fixed it for a bit but now is acting up again, we plugged it back in it ran fine a couple times then we start acting up, we removed the flapper from the throttle valve that didn't fix it, I do have some data logs of it acting up and not acting up if some knows what they are looking at.
thanks kevin

 

[2004LB7]

Can you post up the logs here?

 

[kvw4x4]

I can email them not sure about putting them here. I'm not real tech savvy

 

[AZlml]

Sounds like my truck right after I did the cp3 and delete. Rail pressure would drop to like 3k anytime you would get in it. Just needed to be re-tuned after I sent data logs. If you have a cts2 you can watch rail pressure.

 

[OregonDMAX]

Tuning the cp3 in an LML isn't a one adjustment fixed all kinda deal, took 3 different tunes to get it just right. If you don't send MotorOps a lol of what the truck is doing they will never be able to fix it

 

[kvw4x4]

I sent them I think 6 different logs I took of truck, some of the logs I drove truck without having it act up and some of the logs I drove truck and made it act up, I did each log from taking off through cycle up to speed and then till I slowed down and stopped, motor ops has the tunes its just been a couple days since and I haven't heard anything,

 

[kvw4x4]

After lots of people looking at tuning and messing with other stuff someone suggested the on engine injector fuel return lines. Where the injectors returns from each side of engine meet up and y together to head back to tank there is a type of pressure regulator. These lml injectors needs 150 psi of back pressure to work right. We ended up replacing it and it fixed our problem. Thanks Neal at all in truck performance

 

[duramax on fire]

Very good info. Thanks for posting the suloution.

 

[CTSLAYER]

I am having a similar issue with my ‘16, with pretty much all of the same mods. I have replaced frpr on the front of the fuel rail, fuel filter, changed tunes from motorops, etc. Just curious what pressure regulator you’re talking about behind where the return lines meet, and if you have a part number. I am almost certain this is what’s happening with mine. Thanks in advance

 

[2004LB7]

I am having a similar issue with my ‘16, with pretty much all of the same mods. I have replaced frpr on the front of the fuel rail, fuel filter, changed tunes from motorops, etc. Just curious what pressure regulator you’re talking about behind where the return lines meet, and if you have a part number. I am almost certain this is what’s happening with mine. Thanks in advance

Fuel Return Pressure Regulator Kit - 2011-2016 GM LML 6.6L RB40445130020

0445130020 - Fuel Return Pressure Regulator Kit for 2011-2016 GM LML 6.6L Duramax Diesel pickups.

usdieselparts.com

 

[CTSLAYER]

Fuel Return Pressure Regulator Kit - 2011-2016 GM LML 6.6L RB40445130020

0445130020 - Fuel Return Pressure Regulator Kit for 2011-2016 GM LML 6.6L Duramax Diesel pickups.

usdieselparts.com

Thanks for the reply, I’ll replace this and see what happens

 

[2004LB7]

Thanks for the reply, I’ll replace this and see what happens

Contact one of the vendors here and see if they can get you the required parts. It helps support this site and thus helps us help you

 

[CTSLAYER]

Contact one of the vendors here and see if they can get you the required parts. It helps support this site and thus helps us help you

Will do

 

[nate2112]

Will do

that ever fix your problem as well?