LBZ: Tuning new cp3

DetailsUnlimited

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Oct 26, 2009
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Benton, Ar
Bought a new cp3 cause the old one was giving me issues. Now that I have got it to idle right it surges as the psi increases. The psi gauge is jumpy as psi increases. How do you tune this out. Smooth the psi increase.
 

sweetdiesel

That's better
Aug 6, 2006
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B1015 I have adjusted the idle. Can the rest be smoothed out with the B1015 or anther calibration?
If you have a lbz and swapped pumps with a new lbz pump and something is wrong? your tuning could be wrong.


flash in a stock tune, if you still OFF, then its a hard part,if not then your tuning is off
 

DetailsUnlimited

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Oct 26, 2009
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Sent a new pump to Danville to mod. Had to change the cal B1015 to get the knock and overfueling out. Now running good with stock tuning just the psi is irratict as it increases. What do I change to smooth this out now? Thx
 

paint94979

Beer Nazi
Sep 18, 2006
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Sent a new pump to Danville to mod. Had to change the cal B1015 to get the knock and overfueling out. Now running good with stock tuning just the psi is irratict as it increases. What do I change to smooth this out now? Thx

You need to rescale your regulator current table
 

GMC_2002_Dmax

The Still Master
Modifying a pump regulator usually results in inconsistent pressure vs. current.

If anyone has ever seen a regulator disassembled it has a triangular window and as the current is decreased or increased by the ecm the spring moves the window ( triangle ) that lets fuel into the CP3.

Bosch built this to exact specifications for a reason, when you mod it with a dremel, die grinder, file, whatever it's like resizing a crankshaft with a belt sander and 36 grit belts !

I am not saying Mark did anything wrong but most people who mod them only open up the triangle at the very bottom so it only effect WOT.

That being said you better be prepared to spend a lot of time changing those amps a little here and a little there to get it right and you may never get it perfect depending on how it was modded and what else what modded.

I had a modded regulator from Super Diesel back in 2006 and ran it for many years until my pump weakened enough to justify an LBZ pump swap. Even with a Road Runner ECM in my 2002 it took me a few weeks to get it just right.

Good Luck

;)
 

Cougar281

Well-known member
Sep 11, 2006
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St Louis, MO
What Tony said, plus if you happen to have one that is sticking like the first Wicked Diesels one I got, it'll be hell to try and get right beause nothing will work the same twice.
 
Sep 10, 2008
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Morehead City, North Carolina
I had the same issue but it was a modified lly reg and pump on my lb7. When we first started it after injector and cp3 swap I thought the motor was going to jump out of the truck. I guess when you hold 26k psi at idle will make it sound like a ragged out 7.3. After a few tries playing with voltage Dustin g9t it worked out just fine.
 

DetailsUnlimited

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Oct 26, 2009
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Benton, Ar
I had the same issue but it was a modified lly reg and pump on my lb7. When we first started it after injector and cp3 swap I thought the motor was going to jump out of the truck. I guess when you hold 26k psi at idle will make it sound like a ragged out 7.3. After a few tries playing with voltage Dustin g9t it worked out just fine.

Dustin said to change the first three to get the truck to idle right and yeah I thought the motor was going to blow up!! Was the psi jumpy through the rpm and how did he fix this. The idle is good but driving you can hear the motor surging because of the reg. The rail gauge in the truck is jumpy while driving.
 

Cougar281

Well-known member
Sep 11, 2006
1,809
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St Louis, MO
If it's a modded LBZ reg into a LBZ truck, you shouldn't need to mod anything to get the truck to run right. My modded reg needed no changes to run properly once I converted the truck over to all LBZ stuff. When it was a LLY, that's another story. Got ot "ok", but never really got it 100%.
 

x MadMAX DIESEL

<<<< No Horsepower
Dec 30, 2008
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Lexington, Ky
I dont know Mark, and he isnt a vendor here.


why dont you ask him for help?
Doesn't mean he shouldn't be allowed to ask for help here :confused:

If it's a modded LBZ reg into a LBZ truck, you shouldn't need to mod anything to get the truck to run right. My modded reg needed no changes to run properly once I converted the truck over to all LBZ stuff. When it was a LLY, that's another story. Got ot "ok", but never really got it 100%.

x2
 

DetailsUnlimited

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Oct 26, 2009
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Benton, Ar
I did get to talk to Mark today and helped me dial in in better. Thx Mark! The pump must of been a little more flow than it was suppose to be.

And this forum is to ask question and learn from yours and others mistakes so we can help each other regaurdless who you buy it from!
 
Sep 10, 2008
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Morehead City, North Carolina
Dustin said to change the first three to get the truck to idle right and yeah I thought the motor was going to blow up!! Was the psi jumpy through the rpm and how did he fix this. The idle is good but driving you can hear the motor surging because of the reg. The rail gauge in the truck is jumpy while driving.

Only the idle was rough as sh*t. Everything else felt great. Maybe that is something you could discuss with him. Let me know if you can't get in touch.
 

sweetdiesel

That's better
Aug 6, 2006
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Doesn't mean he shouldn't be allowed to ask for help here :confused:


Ask away! But i have no idea what mark has done to the pump? Regulator / suction pump???


x2

I did get to talk to Mark today and helped me dial in in better. Thx Mark! The pump must of been a little more flow than it was suppose to be.

And this forum is to ask question and learn from yours and others mistakes so we can help each other regaurdless who you buy it from!


Yes it is.....And I dont care who you buy stuff from.

But if we dont know whats done.....How can we help?:confused: