Sluggish lb7

[Night rider 22]

Hello guys new to this site, I have a 2001 lb7 that seems really sluggish, all my info should be in my signature, from a 0-60 launch it launches fine. Once it shifts into 3rd and 4th it takes forever to shift and pretty much falls on it's face even when I had my efi live in it, I put it back to stock so I can get it retuned for my injectors, I replaced the fuel filter, cleaned the air filter, and maf, my 0-60 was 22 sec, pretty pathetic. Thinking time for transmission build?

 

[Night rider 22]

Anyone? Figured I'd try this forum since I got no help on the last forum

 

[Dirtymaxx03]

Your stock cp3 may not be keeping up with those injectors like it should.

 

[Dirtymaxx03]

Is the engine revving and not pulling by chance?

 

[Night rider 22]

Yes it's revving and not pulling for a few seconds but when it finally shifts it pulls, even when I'm merging onto the highway all it does is rev and slowly gets to speed,also my egts were reading 1500 during my 0-60 probably normal with no tuning?

 

[Ne-max]

What is you commanded rail pressure vs actual rail pressure? You running a lift pump? Could be a fueling issue or your trans not liking the extra power.

 

[Night rider 22]

No lift pump yet I have one iv just been waiting on some nice weather to instal it, iv been planning on getting the trans built it's stock with 241,000 on it just hard to save the Money

 

[2001-GMC-LB7]

Any Codes?

When I started slipping the trans it would go right into limp mode.
Shut truck off and on again to clear and would run fine till the next slip.
This will get worse and more often until you build trans to take added power.
I did have mine Built and now no issues with trans.

Also check what OS you are running, I had to run the newer OS I believe it is from an 02, to get my truck to RUN and not fall on its face because of boost issues in the older OS.

Here is what I was told and it fixed it!!!

Here is the deal on 2001 OS and duramax issues.

During EFI-Live beta testing in 2005/2006 of which I was a part of it was discovered that some handheld tuners did not properly remove the speed limiters on the trucks and the return to stock option did not return the trucks to stock calibrations.

It was the biggest problems on 2001 trucks, in addition the 2001 computers are unique as far as the part numbers, they differ physically from the 2002-2004 LB7 computers.

It was found that the 2002 OS/15186006 was the best OS to use in all 2001/2002 trucks and for the last 7 years I have updated all of the 2001 trucks I have tuned to a 2002/15186006 OS.

I use only clean TIS files which have never been corrupted by a flash tuner.

So to answer your question it could be the OS, it could be a limp issue, low rail psi, etc.

If you want a clean/stock/OS just tell me your options for transfer case switching, electronic or manual and if you have a short or long bed and I will email you the correct stock file for your truck and you can start there.

Or you can purchase a tuned ecm with a switch from me and send the 2001 ecm back as a core.

Tony programmed my truck and it never ran better.

I also had GM update the Trans OS as I was having issues with trans going into neutral between 2nd and 1st when slowing down. Sometimes it would stay in neutral until I stepped on pedal then bang into gear.
OS update did fix that issue also...

 

[Night rider 22]

I have no codes last code a threw was over boost, when I had the efi live tuning deleted out the guy re flashed it to an 02 cause he updated everything