Bracket Talk
Duramax low fuel rail pressure?

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https://drr.infopop.cc/eve/forums/a/tpc/f/80760912/m/1247083896

March 30, 2022, 09:22 PM
Bruce Williams
Duramax low fuel rail pressure?
I use a 2006 Duramax LBZ dually for towing our race car trailer.
On long grades under heavy load I get the low fuel rail pressure code.

Truck only has 65K on it. It gets regular oil and fuel filter maintenance.
I have replaced the O rings on the fuel filter head.
Truck sits most of the time. Just gets used on race day.
I run an Edge Attitude with juce programer which allows me to pull and clear the code on the fly which is nice. Im getting ready for the upcoming las Vegas race in April and would like to see if I can get the codes to stop.

Any ideas if a lift pump can cure this problem?


Bruce Lee Cool

Experience is what you get when you don't get what you want.
March 30, 2022, 10:06 PM
banjo
I had the same problem on my truck. There is a pressure relief valve that gets weak. They sell shim kits to increase, or you can go with something like this. This fixed the problem on my truck.

https://ppepower.com/collectio...riant=42081658077427


Bill Simpkins
74 Nova
SBC 406
3240 pounds
Speierracing heads

60 1.27 (10/16)
1/8 6.03@111 (10/16)
Best 9.87@131 on the rev limitor 1 Feb 2013


nova

quarterpanelview

wheelie

FTI Converter
www.speierracingheads.com

March 30, 2022, 10:09 PM
rusty
t is not a weak CP3 pump,i have had this happen to my LBZ sevaral times and heres the most notorious ones..
weak FRV(Fuel Rail Valve),how to fix is either replacing with stock,putting a shim kit in or a race valve in.
Injector Control Mobule Harness,if it is bad it will cause stuff like that also.
bruce this was from a forum


honesty is the best policy,insanity is a better deffense
1.036, 6.16@ 224

March 30, 2022, 10:13 PM
banjo
Here is also a link that explains what is happening and how to test.

https://kennedydiesel.com/docs...tle%20Test%20etc.pdf


Bill Simpkins
74 Nova
SBC 406
3240 pounds
Speierracing heads

60 1.27 (10/16)
1/8 6.03@111 (10/16)
Best 9.87@131 on the rev limitor 1 Feb 2013


nova

quarterpanelview

wheelie

FTI Converter
www.speierracingheads.com

March 31, 2022, 12:00 AM
Bruce Williams
Great information.
Thank you.


Bruce Lee Cool

Experience is what you get when you don't get what you want.
April 03, 2022, 02:56 PM
Alaskaracer
Earlier years have an issue with injectors as well. Excessive bypass. I'd have it taken to a reputable shop for diag.....I've done A LOT of injectors on those.......


Mark Goulette
Owner/Driver of the Livin' The Dream Racing dragster
www.livinthedreamracing.com
"Speed kills but it's better than going slow!"
Authorized Amsoil Retailer