Wideband and fuel trims

[gtpsleeper]

Getting back into trying some new stuff and am curious about something.

When I first changed to e85 I did all my tuning pretty much in open loop (never was able to log my WB so just eye balled the WB to maff hz). I have then since changed back to closed loop in an effort to dial in my lower rpm fuel trims. I didnt have time to mess with the tune for a while as life kinda got (and still is) a little crazy.

Now, after the orginal switch from OL to CL, I fine tuned the lower maf numbers (which were not too far off) and left off there. I have left it alone since then and want to finally get this thing as perfect as possible (Idle trims, timing changes, adders and maybe figure out some startup).

Now, my main question is, do I trust my WB or my LTFTs when dialing this thing in?

Ex: At cruise, my LTFTs will be locked at 0 but my WB will be jumping around 13.9-14.2 (WB reads lambda and converts) and at WOT my WB will be reading almost dead on my command WOT afr but my trims will be ~+10...

Im not sure if this is an e85 thing or what but my question is which one do I go off of? I need to set up my WB logging I just cant figure out where my issue is on it.

Thanks in advance

Jarred

[507]

Hope I can be of some help.

WB for Full throttle, LTFT or STFT for Idle & cruse, or MAF - AFR Error.hst.

[gtpsleeper]

507,

Thats kind off the approach I have been taking but the issue with trying the MAF-AFR Error is my WB is unable to actually log right now. And, even if it could, the WB and the fuel trims would disagree with one another and I wouldnt be getting anywhere with that route.

IIRC the WB is not very accurate <3,000 rpm but I wouldn think it would be THAT much of a difference.

[507]

I respect that, and thank u. It well all work out in the end.

Peace & respect.

[Dr. Nopps]

"I just cant figure out where my issue is on it." You hadn't posted your tune but seeing as you asked for assistance here my first thought would be things aren't working out right because you didn't follow to the letter the exact steps in sequence outlined in "The Russ K Method", but just guessing mabey you did . Try resetting to stock, then get your wideband figured out, and use his method - exactly. He mentions weird stuff may/will happen if you try to take any another approach at air/fuel tuning with these motors, you may have in fact just described some of that stuff.
http://www.hptuners.com/forum/showpo...64&postcount=1

[gtpsleeper]

Thats the logic I use when doing any 3800 tuning. The problem with my wideband is not a histogram issue or anything as I have all that done and fine. The probelm I am having is in my connections somewhere as when I log my WB it just reads at a constant 12.X. That issue I am searching for and troubleshooting. However, everything I NEED to log the WB (IE error and maf histograms) is setup and functioning fine. Obviously, I can use this when I find my issue in connecting the WB to HPTuners.

My main concern is when I do get my WB connected and reading what the display reads, should I be worried it doesnt coincide with my LTFTs.

to reinerate my first example, if the WB is giving me a lambda of .9 at cruise but my LTFTs are reading zero (command being stoich).... should I make adjustments via the WB readings or the LTFT readings?