Low rail pressure!!

lb7duramax1993

New member
Jan 24, 2013
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Mooers,ny
Did my first pull with my truck and still getting a change fuel filter message. It only does it on my big tune which is a 530 danville tune. It will do the same thing on the street. I have a air dog 150,race plug,and deleted my factory fuel filter. What could be causing this ? Doesn't really seem to lose power.
 

mike diesel

I'm alright.
Sep 6, 2012
4,005
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36
SLC, Utah
Dead cp3 or injectors returning to much fuel would probably be the things to look into since it sounds like the other bases are already covered. Verify the lift pump is maintaining positive pressure also.
 

lb7duramax1993

New member
Jan 24, 2013
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Mooers,ny
Two things I was thinking but hoping that it's not going to be. I don't have a rail pressure gauge or fuel pressure. Being I have a pull tonight would I be better off running my 460 tune? Didn't really seem like the truck loss power through the run. Here's a link to the video.
[FONT=&quot]https://video-ord1-1.xx.fbcdn.net/hvideo-xtf1/v/t42.1790-2/11747722_10204841262134772_1517534477_n.mp4?efg=eyJybHIiOjcyNywicmxhIjo1MTJ9&rl=727&vabr=404&oh=54bd9a974fff5eebf994f1fe2ebfe16a&oe=55BB99DC[/FONT]
 

Bonestock

Active member
Aug 9, 2010
1,358
1
38
Worland Wy
What year of truck? Sounds like LMM? Anyhow log your rail psi and see where you are @. A 530hp LMM or LBZ tune can be enough to drain the rails on a stock cp3 / injector truck with around 3000-3100 usec. This would require more cp3. I went with an exergy sportsman and it helped out quite a bit. If you want to really step it up an exergy 10mm cp3 is what I used to run and they are bad mothas!
 

lb7duramax1993

New member
Jan 24, 2013
21
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Mooers,ny
It's a 07 lmm with 115 k and it does have a fuel rail plug. I've actually been looking into those pumps but unfortantly don't have the funds for one right now. It's weird because it don't give me a rail pressure code just brings fuel filter life to zero.
 
Jan 28, 2015
961
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Ohio
Mine did this a few weeks ago. Do a bottle test on the rail plug or get an adjustable lift pump. My airdog 165 I do not like anymore. Seems like it doesn't keep up sometimes:mad:
 

Bonestock

Active member
Aug 9, 2010
1,358
1
38
Worland Wy
PPE has a flowed fuel fitting that goes in the the pressure rail. Fleece did some flow test with the fittings here:

https://www.youtube.com/watch?v=m95OEIeX6uQ

https://www.youtube.com/watch?v=3J7ZoQrKbzA

http://proshop.summitracing.com/parts/ppe-113071000



I have my Lmm squeezed to the bar with a Exergy Sportsman Pump. I have a ton of logs to look back on. I am going to install these fuel rail fittings and retest and compare logs. I will post results once done. I do have an airdog 165 set @ 15psi and 1/2" line ran to rail with filter deleted. I would love to gain another 1000 psi @ the rail and be able to sustain more duration!

It is very common for the stock setup cp3/injectors on lmm/lbz to fall off the face of the earth around 3100usec 100mm3 and up even with fuel rail plug and lift pump. The cp3 is out of wind @ that point for the most part.