Fuel rail pressure low

Mr-Jack

New member
Sep 17, 2014
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Im not a big tuner guy just want the power when I ask for it.

I have an 08' that I pulled the emissions out of. DPF/EGR deleted. PCV bypass, CAI, and a 4" exhaust with a muffler to quiet it down. Also have an H&S mini maxx tuner. The tuner has 4 power settings that you can switch on the fly.

When I select the highest tune (believe it to estimate 100hp over stock) and mash on it going up a grade... the truck goes into a somewhat limp mode and I lose power. The info displays a CEL telling me theirs insufficient fule rail pressure. I can pull over and reset the DTC and it will be fine until I ask for that amount of power again. I don't drag race, I mainly use it for hauling trailers... but I do like to feel the power sometimes.

My question is, do I need to get different (than my currently stock) injectors? Do I need a better fuel pump? Idk why I get this message, but I need it to not happen while I'm pulling the grade on the pass.
 

Burn Down

Hotrodder
Sep 14, 2008
7,092
28
48
Boise Idaho
Fuel lines are kinking and restricting fuel flow. Ck the lines at the left rear of the engine, were it turns into soft line at the quick connector
 

hondarider552

Getting faster
May 28, 2008
10,627
2
36
34
Arizona
Lol. Clearing the code doesn't make the problem go away. Probably should stop towing with a hot tune or you will have more problems ..
 
Jan 28, 2015
961
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Ohio
Could be many things. Cp3 or injectors bad or returning too much fuel. You should do a bottle test first to see if a fuel rail plug will solve your problem. Does the truck have a lift pump installed? How old is the fuel filter? Id start with rebuilding the filter head. Checking all soft lines and installing a new fuel filter.
 

Mr-Jack

New member
Sep 17, 2014
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No lift pump and fuel filter is probably about due for replacement.

Pardon my ignorance, but what's a bottle test?

I don't run that tune often since this started happening.
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,661
5,808
113
Phoenix Az
No lift pump and fuel filter is probably about due for replacement.

Pardon my ignorance, but what's a bottle test?

I don't run that tune often since this started happening.

you need a lift pump but right now that low rail pressure is probably keeping your trans alive because you have no respect for what the allison can and cant hold trying to push that power while towing.

put a lift pump on it, it will solve your issue but you will kill that trans next.
 

Mr-Jack

New member
Sep 17, 2014
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I should also note that I don't run that tune towing heavy... honestly have only ran that time a dozen or so times since I've had it.

I know resetting the DTC isn't going to fix the problem... hence why I'm in here getting advice.

I'll look into a lift pump and check my fuel lines. I've read up on lift pumps before. Some are pricey and some are more affordable. Any recommendations on a decent one that won't break the bank?

Thanks fellas.

Jack
 

BlkMax

Member
Sep 1, 2008
743
4
18
Wasilla, AK
I like the Kennedy Diesel single centrifugal pump for stock and mild tune trucks, and the twin pumps for trucks with more mods. They are quiet and work. The price for the single pump only kit is <$400.


Here is my Kennedy twin pump on Emma; it is not the Kennedy install kit...
Burn should recognize this :hug:
 

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Burn Down

Hotrodder
Sep 14, 2008
7,092
28
48
Boise Idaho
I like the Kennedy Diesel single centrifugal pump for stock and mild tune trucks, and the twin pumps for trucks with more mods. They are quiet and work. The price for the single pump only kit is <$400.


Here is my Kennedy twin pump on Emma; it is not the Kennedy install kit...
Burn should recognize this :hug:

:thumb: I have a new fuel filter you need to switch over to, it has way tighter synthetic media for high pressure common rails 416-1225 ultra high efficiency plus. Cat did valve seat erosion tests with the 1r0749, Baldwin, Donaldson and a few others against that 416 filter the wear difference on the seat was dramatically better with the newer filter.
 

BlkMax

Member
Sep 1, 2008
743
4
18
Wasilla, AK
:thumb: I have a new fuel filter you need to switch over to, it has way tighter synthetic media for high pressure common rails 416-1225 ultra high efficiency plus. Cat did valve seat erosion tests with the 1r0749, Baldwin, Donaldson and a few others against that 416 filter the wear difference on the seat was dramatically better with the newer filter.

Thank you, I need to order some new filters anyway for stock. I'll be getting the 416-1225. :D:D
 

Mr-Jack

New member
Sep 17, 2014
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0
0
Thanks for the suggestions... might be a stupid question, but does this eliminate the need for the stock fuel filter? It's a pain in the ass replacing that filter and my inner fender has seen better days.