commanded WOT Afr Im confused

[blazinblue]

well just started doing my auto ve on my 03 silverado,6.0. i have commanded my pe at wot to 12.88-12.98. when ever im logging or just flash something into the pcm it actually follows it pretty close. I let the truck cool off for a day or so and i take it at WOT and my AFR goes to 11.5-11.7:shock: what am i doing wrong??

Tune is in SD, followed the auto ve.


here is a log that shows when it gets to the 11.5 area:

the second log is when i removed 2* of timing flashed it and and WOT follows close to commanded

Also this is my current tune:

[blazinblue]

i did notice on the first log the long fuel trims stay at 14.1%-16.4%? and on the second log they stay at 0.

[joecar]

I didn't get a chance to look at your files, but I sent myself a reminder.

[SOMhaveit]

Are you trying to do Auto VE without a wide band o2sensor? I don't see any analog voltage from a wideband. You are logging more than 24 channels and you need to dump some of the unnecessary stuff. Your TPS looks goofy. I saw 15% TPS at around 900 RPMs. You have your power enrichment set to kick in at 90% throttle position. I think that might be playing with fire.

[blazinblue]

i do have a wideband im logging serial, you can see my wbo2afr in dashboard. what i dont understand is that when i flash my original tune that i modified from auto ve my commanded 12.9 wot follows closely as you can see in the 2nd log.

I let the truck sit for a while with that same tune and i go for a ride and go to wot and it falls down to the 11.5 area, see 1st log.

Do i have to reset the LTFT's before i drive the truck with the original tune?

[blazinblue]

Another log today that shows afr at wot around 11.9 with this updated ve table.

it was fine as soon as i flashed the tune, it was at 12.9 at wot. I let the truck sit for an hour and look what happened:doh2:

[blazinblue]

:confused:

[SOMhaveit]

Disable the LTFT & see what happens.

[blazinblue]

Disable the LTFT & see what happens.

ill try it in a few, see what happens. What table is it?

[swingtan]

Turn off the NB O2 sensors.
Disable LTFT


You need to follow the Auto VE guides if you are trying to tune the VE. These guides will tell you to do both of the above. Why do they say to turn off the O2's and LTFT?

In your log, you are commanding 13:1 at WOT, but while driving normally you are in CL mode and the PCM is learning what fuel trims are needed. Driving normally the PCM had LTFT's of 14%, which is quite high. During WOT, the LTFT's are used to correct the mixture, from the leaned values. In your case, at WOT you have LTFT's of 9%

So if you command 13:1 AFR and then add 9% more fuel.....

9% of 13 = 1.17

take 1.17 from 13:1 and we get.... 11.83:1 "actual"commanded

regards,

Simon

[blazinblue]

what calibrations do I disable? is it B3801? Also on which tunes do I disable LTFT and turn off NB O2's?(SDAutoVE or Original tune)
Sorry new to this AutoVE , I did exactly everything as in the AutoVE tutorial included with EFIlive


Turn off the NB O2 sensors.
Disable LTFT


You need to follow the Auto VE guides if you are trying to tune the VE. These guides will tell you to do both of the above. Why do they say to turn off the O2's and LTFT?

In your log, you are commanding 13:1 at WOT, but while driving normally you are in CL mode and the PCM is learning what fuel trims are needed. Driving normally the PCM had LTFT's of 14%, which is quite high. During WOT, the LTFT's are used to correct the mixture, from the leaned values. In your case, at WOT you have LTFT's of 9%

So if you command 13:1 AFR and then add 9% more fuel.....

9% of 13 = 1.17

take 1.17 from 13:1 and we get.... 11.83:1 "actual"commanded

regards,

Simon

[SOMhaveit]

Yes, disable B3801 and disable B4206.

[blazinblue]

Yes, disable B3801 and disable B4206.

for auto ve and my original tune right?

[SOMhaveit]

For your Auto VE tune. That's the tune you should have loaded in the ECM while you are tuning the car. You saved the original tune so you would have it to reference in the future if needed. You are working off the Auto VE tune now and that's where you need to stay and adjust your volumetric effeciency to get your AFR dialed in.

[joecar]

+1 on what they said above.

Work from your AutoVE tune file... this is supposed to now be your current tune file... work from it only (saving successive edits with the incrementing number after the filename)... get your VE done before you do anything else... did you sanity check your IFR table from the spreadsheet (enter your own measured rail pressure)...?

Your tune files show MAF disabled (logs confirm with DTC), but NBO2 feedback/trim still enabled (logs confirm with LTFT/FUELSYS)... go back over the AutoVE doc and make sure you got all the setup.

VE table doesn't look right, might want to start again (but increase the VE table by only 4%, not 15%)... operate the throttle smoothly and progressively... remember to apply the throttle transient filter as spec'd in the AutoVE doc.

[blazinblue]

im running stock injectors, i will start from a stock ve and add 4%. also on the ve tutorial says to bring it to SD Closed loop just copy your ve table into your current original tune right? so if i start with a stock tune the only thing im disabling is the MAF to bring my original tune to SD.

tutorial does not say to disable LFT correction or O2 sensor on your final tune. Just on your autove tune.

I will do auto ve again and come back with some logs,Thanks fellas

[joecar]

Concentrate on OLSD for AutoVE first, post tune/log files of that... your results will determine what has to be done next.

[blazinblue]

did a couple autove logs today, what is the difference when applying just the ben filter and emptying cells under 50? when i click to hide cells under 50 im left with less cells even thou every cell is above 50 on the log.

[SOMhaveit]

You aren't looking at something correctly. You have quite a few cells with n < 50. 46 of the cells with a value have n< 50.

[joecar]

Hi BB,

Emptying cells under 50 counts: ignores data that has "insufficient" statistical occurrence.

BEN filtering: ignores data during MAP/throttle transient conditions (which would otherwise skew the BEN corrector).

I'll look at your logs when I get home tonite.

[The Alchemist]

I was gona say that :hihi:

what he's tryn to say is that your VE table is still a bit out causing high fuel trim values , that are learned and retained by the PCM, that are then imposed on your full throttle runs as corrections. When you reflash a PCM any fuel trims are returned to "zero" which is why your car runs a correct commanded AFR after a reflash.
MIke





Turn off the NB O2 sensors.
Disable LTFT

You need to follow the Auto VE guides if you are trying to tune the VE. These guides will tell you to do both of the above. Why do they say to turn off the O2's and LTFT?

In your log, you are commanding 13:1 at WOT, but while driving normally you are in CL mode and the PCM is learning what fuel trims are needed. Driving normally the PCM had LTFT's of 14%, which is quite high. During WOT, the LTFT's are used to correct the mixture, from the leaned values. In your case, at WOT you have LTFT's of 9%

So if you command 13:1 AFR and then add 9% more fuel.....

9% of 13 = 1.17

take 1.17 from 13:1 and we get.... 11.83:1 "actual"commanded

regards,

Simon

[blazinblue]

Well i went to the 1/4 track yesterday heres my log of the run, my wot timing keeps jumping around, need some more work on my auto ve since my wot afr moves too.

[joecar]

Get your AFR down to 12.6.

Smooth your VE just a little, and extrapolate it across, and do another iteration, be sure to use smooth throttle to get better data.

Timing at WOT looks good and consisent.

Also log DYNCYLAIR to index into spark table.