Need some ideas

6.6lb7duramax

New member
Apr 10, 2017
13
0
0
I have a 04 lb7 I have ppe tuner exhaust intake truck has 200k it seems to run really good but is sluggish off the line and I can't seem to get much more that 5psi holding the break every now and then I'll be able to build boost 15psi any ideas why this is?
 

ChrisPerry

...........
Apr 4, 2016
209
6
18
Ventura, CA
Have you checked for boost leaks? Hot side tube at steering box is notorious for a leak.

Do you have a boost increase valve?

What level is the tuner set to?

Lift pump?

What elevation are you at?
 

TheBac

Why do I keep doing this?
Staff member
Apr 19, 2008
15,677
1,944
113
Mid Michigan
Moved to proper LB7 forum.

As Chris asked....need far more info than what you've given.
 

6.6lb7duramax

New member
Apr 10, 2017
13
0
0
I have boost valve tuner is normally set on 2 or 3 out of 5 it's just the ppe standard no lift pump will build around 26 or so of boost but it's a slug off the line it has a 6in lift with 35s my buddy has a 01 with edge and that will break the tires lose off the line
 

ChrisPerry

...........
Apr 4, 2016
209
6
18
Ventura, CA
I have a 6" lift with 35's also, with my PPE on level 3 won't smoke them either. It's 120hp at the flywheel, only about 55-60 at the wheels. Now on level 6..........:driving: :woott:
 

aashton1206

Member
Sep 3, 2015
172
0
16
How old is your CP three pump


2004 Silverado Cali lb7, Airdog ll 165, fresh sticks at 325k, custom tuning on v2 by Rick Fletes, 33x12.5 nittos at on 20 inch American steal wheels, modded factory air box, Profab Intake Horn, Batmo Wheel, Turbo port and polish, Full EGR Removed w/ fed belt, 3.5 inch MBRP Downpipe, Full five inch MBRP Exhaust, 10mm lbz cp3 pump, Dual Yellow Top Optimas, High Output Alternator, Cognito Pittman and idler w/ support kit, Cognito Contol arms, Drilled and Slotted Rotors on all four Corners, Custom Y Bridge.
 

6.6lb7duramax

New member
Apr 10, 2017
13
0
0
Iv read on some other forms that it might be tourqe management is this truck Is this true on a 04? If turned off defuling on the tuner that don't really do much other than when it shifts i don't really have a heavy foot or spin my tires but if I take it to a track or truck pulls is like more that 5psi for a launch i plan on getting a tranny and efi and a lift pump nothing crazy I would like like to know if anyone else has had this problem before I start spending money there's no cel and other than slow off the line and not building boost at the line it runs fine and not haze out the tail pipe no blow by and when it dose spool it's decently fast for being lifted and just a tuner
 

aashton1206

Member
Sep 3, 2015
172
0
16
My first cp3 got weak at 140k and from there it was shit but never threw a code till I replaced it at 320k. Night and day difference. Your other option is your tuning. But the cp3 is a support mechanism so your better to start with that.


2004 Silverado Cali lb7, Airdog ll 165, fresh sticks at 325k, custom tuning on v2 by Rick Fletes, 33x12.5 nittos at on 20 inch American steal wheels, modded factory air box, Profab Intake Horn, Batmo Wheel, Turbo port and polish, Full EGR Removed w/ fed belt, 3.5 inch MBRP Downpipe, Full five inch MBRP Exhaust, 10mm lbz cp3 pump, Dual Yellow Top Optimas, High Output Alternator, Cognito Pittman and idler w/ support kit, Cognito Contol arms, Drilled and Slotted Rotors on all four Corners, Custom Y Bridge.
 

6.6lb7duramax

New member
Apr 10, 2017
13
0
0
I have good rail pressure around 4500 5000 at idle and at wot it'll hit around 25000 did you lose pressure when it was getting week?
 

aashton1206

Member
Sep 3, 2015
172
0
16
I lost a little bit, as soon as I got a 2 percent drop I replaced it. My fpr that came with my cp3 was brand new and would deliver 7k at idle so I switched it with a modded lb7 fpr and have had no issues since


2004 Silverado Cali lb7, Airdog ll 165, fresh sticks at 325k, custom tuning on v2 by Rick Fletes, 33x12.5 nittos at on 20 inch American steal wheels, modded factory air box, Profab Intake Horn, Batmo Wheel, Turbo port and polish, Full EGR Removed w/ fed belt, 3.5 inch MBRP Downpipe, Full five inch MBRP Exhaust, 10mm lbz cp3 pump, Dual Yellow Top Optimas, High Output Alternator, Cognito Pittman and idler w/ support kit, Cognito Contol arms, Drilled and Slotted Rotors on all four Corners, Custom Y Bridge.
 

aashton1206

Member
Sep 3, 2015
172
0
16
Fast or air dog, both excellent support, just get one


2004 Silverado Cali lb7, Airdog ll 165, fresh sticks at 325k, custom tuning on v2 by Rick Fletes, 33x12.5 nittos at on 20 inch American steal wheels, modded factory air box, Profab Intake Horn, Batmo Wheel, Turbo port and polish, Full EGR Removed w/ fed belt, 3.5 inch MBRP Downpipe, Full five inch MBRP Exhaust, 10mm lbz cp3 pump, Dual Yellow Top Optimas, High Output Alternator, Cognito Pittman and idler w/ support kit, Cognito Contol arms, Drilled and Slotted Rotors on all four Corners, Custom Y Bridge.
 

6.6lb7duramax

New member
Apr 10, 2017
13
0
0
So I put a fass on and did efi live and that cured my problem I was having but now like 2 times a week it won't start I get out hit the primer under the hood and it fires right up any ideas?
 

6.6lb7duramax

New member
Apr 10, 2017
13
0
0
It'll do it no matter what fuel level is and wouldn't it be leaking if the filter head was bad? It never did this before only now with the fass on it
 

jlawles2

Well-known member
Jan 28, 2010
1,062
40
48
Danbury, TX
With my Air dog, I do not have to prime main filter. It takes about 7 psi to push through the bypass valve in the CP3 and return to the tank. By chance did you hook up the FASS so that it only runs when the engine is running? Check to see that the FASS is running when you turn the key on.