Can someone enlighten about tuning DFCO. i keep looking at that section and having no clue what the hell i'm looking at. also, while we are on the topic of cutting fuel, how do i use lean cruise since it was disabled from the factory.

 

I believe lean cruise will only function on the Holdens, even if you enable it. DFCO confuses the heck out of me too

 

Well i am glad to hear that i am not alone in my confusion.

any clue why it only works in the holdens? arent they pretty much the same as are ours?

 

oh well. another two hours of my life wasted.

Anybody have any way of making this work?

 

Lean cruise cannot be enabled due to emissions. DFCO cuts fuel based on the parameters you are looking at, you can adjust them to have less delay or hold DFCO longer or come on sooner.

 

You can do a quasi lean-cruise using a custom operating system in EFILive, and I'm sure that HPT has something similar. This is the commanded air/fuel ratio table that COS3 gives you in EFILive, if you put higher than stoich numbers in the lighter load cells you can "fake" a lean cruise condition.



What are you confused about with DFCO? What are you trying to accomplish?

 

Heres what thunder is talking about. My table in COS 3 looks similar to this. See the bottom post by kbracing. https://www.performancetrucks.net/fo...ght=map+sensor


how the hell do u do a show post.

I think the lean cruise stuff is disabled in our pcm. Hardcoded in the US pcm pins, the holden one use it. I remember a thread but cant find it

 

so would a pcm from overseas/mexico work?

 

from what i have read, doesnt lean cruise make the throttle response really crappy? and what little do you really save in fuel???

 

I see what you mean, i think i can work that out in HPT but i get a little more experience before i give it a try.

In DFCO, i just dont really understand how to make the most of it. ex. when i let off the gas going down a hill in drive it takes like 10 seconds for DFCO to kick in but if i manually downshift it seems to kick in almost right away, how do i change that? also, is DFCO cutting ALL fuel, or just some and is there a way to change that as well?

i think i'll do a little more searching to see if i can actually make the lean cruise work. i just cant see GM taking the time to hardwire the inability to use lean cruise into our PCMs. it seems more fitting that they just disabled it and there is some complicated way to re-enable it. maybe i will try and get a hold of a stock Holden tune and see what that looks like. Anybody have one?