Auto Tuning - Step-by-Step

[TAQuickness]

Right now I am running Closed Loop SD. I am still logging my BEN and was wondering if I can still use these numbers just like I did when I was AutoTuning? Most of the numbers are around 1.0 but some are not as close probaly because I did not have enough data logged. I only logged about 3 hours of data and tried to hit every cell I could but some were hard to hit.
I was also thinking of just going to Open Loop all the time.
What does everyone think?

Bill

You can definately do this, but I'm not sure what benifiet you would see. While you are in closed loop, the PCM is trimming the fuel based on O2 sensor feed back, so your WB reading will represent the AFR after trimming.

I would think you would get a better idea of what's going on by monitoring your LTFT's.

[leres]

Please email me your screen shots and I will update the doc.

(I PM'ed you Saturday; I made a new screen grab but I don't have your email address...)

The doc says that after autotuning, LTFTs should be good (-4 to 0) for a closed loop SD tune. Would the same be true for a MAF tune?

If you are running CL w/ MAF, then yes, you will still want your LTFT's in the -4 - 0 range

I understand what the range I'd like my LTFTs to be; my question is if I autotune my VE tables and then go back to closed loop MAF operation, will my LTFTs change? If my goal is to bring my LTFTs into the optimal range, is changing the VE tables the answer?

[joecar]

...I understand what the range I'd like my LTFTs to be; my question is if I autotune my VE tables and then go back to closed loop MAF operation, will my LTFTs change? If my goal is to bring my LTFTs into the optimal range, is changing the VE tables the answer?

If going back to MAF changes LTFTs by much, I understand the MAF table then needs to be tuned (and leave the VE table to where you just tuned it to).

[TAQuickness]

[quote="leres"]

Please email me your screen shots and I will update the doc.

(I PM'ed you Saturday; I made a new screen grab but I don't have your email address...)

I don't have any messages in my box. My email address (TAQuickness@houston.rr.com) is also in the first post of this thread.

Thanks in advance for the screen shots!

[Patches]

Got several iterations of OLSD log/update cycles done. Not as easy as one would think even on the backroads I have the good fortune to live around. Got my BEN factor table looking pretty good although I'm sure it could use a few more iterations. Updated the original file, reverted back to CLSD and started to go for a LTFT logging drive when the skies opened up. :( Oh well, tomorrow's another day. :wink:

Had a couple of issues during the logging sessions. Once, I had apparently copied a few low-count, skewed-value BEN cells to the VE table and the car went into reduced power mode a couple minutes into the drive. A quick upload of the previous tune fixed that.

Also, I started getting a flaring start problem (2500 rpm for 3 sec.) about halfway through the process. That disappeared when I loaded my CL tune in but I'll have to see if it returns on cold starts. The idle tuning sticky mentions adjusting Base Spark in Gear and Base Spark in Park/Neutral so I'll keep that in the wings if it returns.

[TAQuickness]

Patches

From my experience, you will want to get your idle dialed in before attempting to tune the VE table.

Idle is where it all starts

[Patches]

Idle is perfect after reverting back to CLSD so far. My buddy had the same experience with his C5 after SD tuning - his idle smoothed out after VE tuning as well. Go figure. I'm sure I have a good amount of tweaking left but the car is definitely running better.

[TAQuickness]

Once you are back into CL, the PCM will learn the LTFT's that make the idle nice.

What are you trims for FTC 19?

[joecar]

Here it is! A complete step-by-step write up for Autotuning

Revised 8.9.05 2355 (GMT-6)

Edit: for the time being, I cannot seem to make the add attatchment work. In fact, it's not even an option. So If you would like a copy of the doc, please email me.

If you would prefer an uncompressed copy of the document, please email me: TAQuickness@houston.rr.com

Do we email you for the 8.9.05 updated doc (I can't find the link to it)...?

[Highlander]

i have been having a problem with the VE Tuning...

After i dial in the VE... pretty much next to 1.0 in the ben factor, i put back cl and they simply go over the place and all of the sudden at WOT it goes 1 full afr richer 11.2 more or less... is there something to do with the OL Fueling?