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helllo i have been reading alot of the posts here for fuel economy and am a little overwhelmed by the info here my back ground is a diesel tech so alot of what you are saying is like a forgin laguage to me. can some one give me some help on tunning this truck for fuel economy, i dont know what to change or really how far to change it. any help would be appriciated
thanks rob
Hello robertsteele,
What OS is the PCM in your truck using ? Common 2007 "classic" truck OS include 12597120 and 12613248.
Regards,
Taz
thanks taz operating system is 12597120 any help is a preciatied like i said tunning for power and economy
Take a look at the “Tuning for Economy” and “CAX Files” sub-forums. This will give you some insight into what others have done successfully, and what avenues may be available.
I believe the Gen III COS upgrades are only available for the 2001 to 2005 OS years (someone correct this if I’m mistaken) - so that option is not available.
Enabling Lean Cruise (LC) is an option with your OS. This was an OEM tuning strategy used on some Gen III Holden vehicles. Depending on where you are located on the globe, and your local emissions requirements, enabling LC may (or may not) cause issues with consistently meeting emissions standards.
Read through the related threads on the Forum, and see if there are any methods that appear to meet your objectives.
Regards,
Taz
hey taz i have looked at the cax files but i am unsure what to do this is like spanish to me im unsure what will help and what will hurt my truck
Hello Rob,
I know what you mean … few things are ever straight forward. If you want, feel free to send me a PM (private message) with your email address, and I will send you some additional information that may answer at least some of your questions.
Regards,
Taz
I guess my question goes along with this post. I'm working on lean cruise in my 2003 GMC Sierra Denali. 6.0L, 4L65E, Volant CAI w/ scoop, '06 silverado e-fans, corvette servo/3-4 piston. Otherwise totally stock.
I enabled lean cruise via the CAX file and found OEM lean cruise setting from a holden "1 tonner". Problem is I don't yet have WBO2's in this truck and am curious how far I can go with this without being able to see actual fuel ratio. I haven't loaded the tune with lean cruise just yet. just wanted to be sure. So am I pretty safe at these factory setting? Take it a little further? Below are the factory settings from the holden tune.
will the Lean Cruise Target AFR table have to be changed due to the slightly bigger engine?
Attachment 11503Attachment 11504Attachment 11505
Thanks guys!
Hello TrueThinker,
You absolutely should use a WBO when initially configuring LC. The values in table B3639 (Lean Cruise Target AFR) are in EQ. These are subtracted from the stoich value in your tune (EQ of 1.00).
If you look at the 2400 RPM row you will see a value of "0.1426" - this subtracted from "1.00" resulting a commanded EQ value of 0.8574. If your stoich value is 14.68:1, this loosely equates to an AFR of 17:1. LC does NOT use the NBO for fuel trims - it runs directly off your VE table. So if your VE table is inaccurate, the commanded fueling during LC will also be inaccurate - being overly lean is a real possibility.
Also, if you plan on trying to run LC in town, or on any route where there are intermittent stops (traffic lights, stop signs) you may want to consider reducing the value of B3635 (Off Idle Timer) - 150 (seconds) is your current value. This means LC will not engage for 2 1/2 minutes after any stop (idle condition). I generally set this to 10 seconds.
Regards,
Taz
Thanks Taz! and thats kinda what I was afraid of. . . while hoping for a "yea! those setting look safe to try without WBO2's" I'll have to do some searching and see what the favorite WBO2's are. I've had a couple autometer set-ups in the past simply because their afr gauge matched my other gauges but as I have no aftermarket gauges in this truck it'll just be a matter of most user friendly and easiest gauge to make blend into the OEM interior.
Thanks again. and on a side note, i've been playing around with the trans tune and definitely am liking the results. Thanks for the head start on that one.
If you have a US vehicle, you need the LC cax file to enable LC and do a full flash, and then populate the LC tables.