Help for a LB7 towing

LBZ ALL BLACK

LBZ ALL BLACK

Member
Aug 29, 2011
45
0
6
Western Washington
Hey guys I am looking for some suggestions to help out my Dad. He has a 2004 LB7 CCSB, and pulls a 30' 5th wheel. He bought it about 3 years ago with real low miles on it, like 40K. He thought it seemed a little under powered from the start, but never had a diesel before didn't know. So bought the 5th wheel, and tells me it won't get out of its own way! So he goes back to the GM dealer and they sell him the FULL Banks package, 6 pack, intake, exhaust. Well its better now, but not real impressive, ok power and fuel economy. The worst of it is when pulling any real hill, with trailer the exhaust temp comes up real fast, 1400?, so he feels has needs to back out of the throttle.

Sorry about the long story, any help would be greatly appreciated. What next, he's about done, thinks he is just throwing money away! Thanks!
 
AubleAK

AubleAK

New member
Aug 5, 2011
781
0
0
30
Glennallen, AK
I have efi live on my truck, and it tows great for a stock turbo truck. I love it. Egts stay cooler also when towing for me. About 1250 at the highest, on a spike.
 
LBZ ALL BLACK

LBZ ALL BLACK

Member
Aug 29, 2011
45
0
6
Western Washington
I was thinking about that, partly because I want to do EFI live on my own truck. I am concerned there could be something else amiss, so was afraid to go there right of the get go.
 
Chevy1925

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,667
5,813
113
Phoenix Az
Banks is pretty good and safe stuff if setup properly. i personally would have the injectors and CP3 checked out to make sure his fuel system is up to snuff. Im sure you know but LB7s are injector eaters. if you got a few returning too much fuel, it can give bad performance. same goes for bad balance rate ones. Low miles doesnt always mean that the injectors will be good.

What size tune is he trying to pull on? how heavy is that trailer? when was the fuel filter last changed on that LB7?
 
Fastorange

Fastorange

New member
Jan 31, 2009
256
0
0
ohio
my truck was kinda like your dads.. it was an 04 with low miles and sat on the lot alot of its life... it always felt under powered but i changed the cp3 and added efi live and it was a hole nother animal
 
Chevy1925

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,667
5,813
113
Phoenix Az
tell him to keep that thing down to around lvl 2 maybe 3 max. that allison will be hating life. not to metion its a good cause of the high EGTs. which ever mode give a 40-50hp increase is my suggestion to tow on. One, cause its gunna prolong the life of the trans. Two, egts will be kept at a much safer level up hills and when he gets the itch to matt it.

is the truck a california emmision truck or federal? it will say on the side of the driver door where the GVRW are and what not. Just fyi, these lb7 stock to a lbz stock are worlds apart power wise though the tuner should have woke it up a good amount
 
LBZ ALL BLACK

LBZ ALL BLACK

Member
Aug 29, 2011
45
0
6
Western Washington
His truck is FED emissions truck. Sorry if I have bad info on fuel return, I am learning about this diesel stuff!

my truck was kinda like your dads.. it was an 04 with low miles and sat on the lot alot of its life... it always felt under powered but i changed the cp3 and added efi live and it was a hole nother animal

What made you change the CP3?
 
Chevy1925

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,667
5,813
113
Phoenix Az
LBZ ALL BLACK said:
His truck is FED emissions truck. Sorry if I have bad info on fuel return, I am learning about this diesel stuff!

my truck was kinda like your dads.. it was an 04 with low miles and sat on the lot alot of its life... it always felt under powered but i changed the cp3 and added efi live and it was a hole nother animal

What made you change the CP3?
Click to expand...

good deal, means he doesnt have a EGR to contend with lol. Usually what will lead most to changing the CP3 is it no longer has the ability to hold desired rail pressure from stock to mild tunes. return rates as well as watching desired rail pressure under WOT (wide open throttle) can tell you if shes worn out or is going bad. you should be seeing a 22-23,000psi actual rail pressure at WOT to its desired of 23,000psi. if its dropping or not close, that will give you a feeling of it running "underpowered". does it mean the CP3 is bad?? not nessacarlily. a collaping fuel line or plugged pickup tube can give the same affect. this is where a return rate helps to verify if the CP3 is good. if its returing alot of fuel, time for a new one
 
Sledhead

Sledhead

Mountain Pass Machine
Nov 29, 2008
884
0
16
BC
I don't know if the Banks does anything to up the boost? The LB7s are mechanical wastegate and most install a PPE valve or just a T off the pressure line to the wastegate.

picture.php


I saw boost increase from 23 to 27 PSI and EGT's drop about 200 degrees.

Towing performance = compound turbos :D
 
LBZ ALL BLACK

LBZ ALL BLACK

Member
Aug 29, 2011
45
0
6
Western Washington
Interesting you should say that, my Dad was just telling he didn't think he had that much boost. He thought he had never seen more than 25, and that was just a quick peak, nothing sustained. I'll look into PPE valve. Can you clean the MAF with regular MAF cleaner, like on my gas rig? Thanks guys!
 
MACKIN

MACKIN

Smell My Finger...
Aug 14, 2006
3,948
1
0
Connecticut
Yes on the cleaner make sure it's free of any lubricants. They sell a cleaner just for what you want at the parts store. Can't really add anything other then what is recommended on testing your fuel system out.

Banks isn't know for making big power but more on the safe side as mentioned. I would have gone a different route. But it is a trade off regardless. Higher the HP the higher the EGT's and transmission abuse.

How much is he towing and how is it not towing?

You'll need at least a Tech II to diagnose the fuel system.
 
You must log in or register to reply here.
Top Bottom