LB7: Rail PSI ?'s

JJK-

JJK-

New member
May 18, 2014
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Utah
I recently had my cp3 replaced along with a bag of parts. I also had my tranny built, has approx 200 miles on it. My injectors (+50hp) have less than 1000 miles. When my pump was replaced the FPRV was also replaced. The efi tuning was changed as well, 5 levels ( 1 economy, 5 hot). The truck pulls very hard compared to prior to having the pump changed out. At approx 70-85% throttle it'll hold 26k rail pressure. When I put it to the floor it drops to 19k (both on the economy and hot setting). The smoke never cleans up, all the way up to 100 mph, heavy coal. It smokes pretty heavy in the economy setting too. The tranny settings haven't been changed in efi, other than some relearning, I think...

My question, is it possible there is something within the tranny settings that are backing the fuel off at full throttle? There is no slippage at all, very tight..
Is it possible the fuel is too heavy, based on rolling that much coal??

Any suggestions would be appreciated.. I'm assuming I'm giving up a lot of ponies not getting it to 26k.....


04 LB7, EFI, FASS TITANIUM 95, Built Tranny, +50 DDP INJ
 
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JJK-

JJK-

New member
May 18, 2014
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Utah
LWATSON said:
Sounds like you need to make a couple logs and get them to your tuner. You say 50 HP injectors, what % over are they?
Click to expand...

I'm not sure on the injectors, they're DDP 50 hp.. I'll see if I can find out. How do I go about logging my efi? I have a laptop, do I need to get an adapter of some kind?
 
LWATSON

LWATSON

future trans limpers
Jul 30, 2008
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Scotland Neck NC
JJK- said:
I'm not sure on the injectors, they're DDP 50 hp.. I'll see if I can find out. How do I go about logging my efi? I have a laptop, do I need to get an adapter of some kind?
Click to expand...
You should have the cable that goes from your V2 to the laptop. You have to download EFI's software on your laptop, select a PID list then log a run.
 
JJK-

JJK-

New member
May 18, 2014
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Utah
LWATSON said:
You should have the cable that goes from your V2 to the laptop. You have to download EFI's software on your laptop, select a PID list then log a run.
Click to expand...

I don't have a V2.. The efi was downloaded to my truck and I monitor/control it through my insight.. I'll see if my buddy has a cable I can borrow..thanks..
 
JJK-

JJK-

New member
May 18, 2014
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Utah
DIESELMAFIAPER.LB7 said:
Should have done a 150 gph not a 95 gph imo but should still be fine stock cp3s should support a pretty big us on 15% nozzles. I'm sure the tuning needs tweaked some still
Click to expand...


Do you think Fass' claim that the 95 will support up to 600hp is overstated?
 
mike diesel

mike diesel

I'm alright.
Sep 6, 2012
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28 psi is way too high. You shouldn't need more than 10-12 psi. I run mine at 12 psi. My fass said it cam preset at 8 psi...i put a gauge on it right out of the box and it was idling at 3 psi....i adjusted it to 12 psi and have never had an issue. Checking the lift pump pressure is a good idea.

The higher the pressure, the less the flow. Your lift pump is set up to flow 95 gph at probably 8 psi. Crank the pressure up to 28 psi and now your pump may only flows 40 gph.

put a gauge on it and set it to 12 psi and call it a day.
 
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