Need tune 2007 Suburban L76
I need a stock engine and trans tune for a 2007 1/2 ton Suburban with an L76 6.0L and 4wd. The 2007 L76 truck tune will not work, nor will a 2008 Suburban tune. Apparently the 07 Suburban is kind of a bastard due to first year production stuff different from truck and later Suburbans.
Thanks
Anybody?
From your posts, it looks like you have been working on this for about a year, and may have been using a 2007 Silverado L76 tune. The 2007 Silverado and Suburban L76 tunes both use OS12614088.
What issues are you still trying to overcome ?
L76 Suburban Tune
They use the same OS but the 07 Silverado has a fuel system control module. It varies the fuel pressure according to demand. 07 Suburbans do not have it. So I am having some drivability issues. I am able to toggle that feature off, but it still runs the same. It is like there are no alternate injection tables to pull from. 08 Suburbans do have the FSCM so it will not work either. Also, the Suburban has a different trans OS from the truck. That's why I would love to get a true 07 engine and trans tune.
Thanks
From your posts it seems that you are not tuning this vehicle yourself, but rather appear to be going back and forth with a tuner.Originally Posted by Maxirat427
Let's clarify a few things ...
The tunes for a 2007 L76 Silverado and a 2007 L76 Suburban are nearly identical. There is no such thing as "alternate injection tables". The absence of the FSCM accounts for an almost negligible difference in injector flow (in a naturally aspirated engine).
In 2007, Silverado and Suburban used the same T42 OS. The 4L65 transmissions typically used OS24239036, while 4L70 transmissions typically used OS24239927 (which was used by both 4L65 and 4L70 transmission in 2008).
If you are tuning this yourself, connect a wideband oxygen sensor, and correct the MAF and VVE as necessary.
If you are using a tuner - find a different tuner. A decent tuner could have used your original LC9 5.3L tune as a starting point for the L76 6.0L conversion.
If you really want a matched pair of original 2007 Suburban L76 4x4 E38 and T42 tunes, you have several options. You can hope that someone on the Forum has one of these vehicles, and will eventually post the tunes. Alternately, most professional tuners have GM equipment and an SPS (TIS) subscription - and could email you these tunes, after bench programming the controllers, and then reading out the tunes with EFILive - but there would be a fee for this service.
L76 Suburban Tune
Thanks for the input Taz. There is no tuner involved, this is all on me. I am really not familiar with the tuning aspect as far as putting in wide band O2 sensor and messing with the tables. I really don't have time to learn, although I would love for someone to show me those things. That was why I wanted factory tunes. I have been through this thing front to back. Every piece on the Suburban now is what it should be if it had come from the factory with an L76. You can just feel when you drive it that it is not right. Funny though, the factory tune from tunefile depot 07 Silverado is different than the factory tune I pulled out of a neighbors 07 Silverado L76. The one on tunefile is running in my truck now (ran script against my LC9 tune). The one I got from the neighbor puts my truck in reduced power mode as soon as I try to drive it. Can find very little difference between the two, but she don't like it.
Anyway, I figured the drivability issues running the Silverado tune had to be with the tables that control injection pulse being different with FSCM.
It was your above quoted post from November of 2014 that caused me to believe that you were using a local tuner.
Trying to tune a conversion without a wideband oxygen sensor is a challenge. You can log the fuel trims, and attempt corrections, but this is can be an imprecise method. The "copy and paste" method of tuning is highly imprecise.
Did you install the 4L70 transmission with the L76 engine, or are you still using the original 4L65 transmission ?
If you are able to post your original (non-modified) ECM and TCM tunes from the LC9, I will take a look, and perhaps could come up with a tune(s) that are a little closer to actual.
Used a local tuner in the beginning to help me figure out the VVT issue. He put together a start-up tune for it but it did not run well (other issues were contributing). Then I found the factory 07 Silverado tune on tunefile depot and it did much better. I have been running it for the past year on it while working out other bugs.
The truck came with a 4l60e with factory turbine input speed sensor like the 4l70 behind L76 trucks (apparently only 07 and 08 4l60e trucks had them), which I had built by a very reputable builder in GA. We beefed everything in it up (Sonnex HD parts, Alto Pack) including GM OEM 5 gear planetary sets. The only part not up to at least factory 4l70e spec is output shaft. We are using the original part there. Everyone I talked to said in this application the original part was fine (stock engine, no power adders, etc...).
I will post the original tunes for you to look at soon.
In general, what would be the process (novice version) after installing wide band O2 sensors to tune the engine?
Thanks for the help.
Last edited by Maxirat427; January 18th, 2016 at 06:16 PM.
For Taz
Try the tune attached below ... it is intended only as a starting point for vehicle specific tuning.
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