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stevedarman
December 27th, 2009, 08:05 PM
Just a few questions with LTFT tuning


I have been following the forum for LTFT tuning and have set the O2 switch point all to 450mv

1. I want to know when i have finished do I set the O2 shitch point back to the
original settings or leave them at 450 mv

2. What is the purpose of setting the O2 switch point to 450mv, What is the problem with tuning without changing
the O2 awitch point

3. After tuning using this method i find the the VE table cell numbers are very low is this normal

mr.prick
December 28th, 2009, 03:20 AM
Are all the VE table cell numbers low or just the low RPM/MAP parts?
Is AFR lean at cold start?

stevedarman
December 30th, 2009, 08:08 PM
The cell numbers are very low
it is rich on warn up

i have put the 02 switch points back to original.
Should i have kept them all at the 450 mv as i that is where i did my tuning
now when i look at the average LTFT they are all alound 1.10

stevedarman
December 30th, 2009, 08:11 PM
when i say the cell numbers are low i mean the ones i have changed using this method

mr.prick
December 31st, 2009, 03:25 AM
After applying LTFT 1.1, you should have higher VE values than OL.
OL fueling can be controlled by changing {B3605}.
Are you reseting LTFTs after making changes?
What is the PID formula and filter you are using for this?

stevedarman
January 1st, 2010, 07:01 PM
Thanks for being patient but i think i am not explaining myself well
I followed the prosedure for LTFT tuning and all the cells went to 0 as expected
then i changed the 02 switch point back to the original settings I am not sure if this is what i was supose to do?
At this point i did another log for curiousity and found all the cells i hit were reading 1.10

Should i have left the 02 switch point at 450mv?
What is the reason for setting the 02 switch point to 450mv or can i tune with the original 02 switch point settings
I am just trying to understand how it works

mr.prick
January 2nd, 2010, 03:35 AM
I leave them @ 450mV
450mV is the "universal" SP for /NBO2s and
the newer GM OS' have a flat 450mV SP as well,
that is my reasoning for flat SPs.

The stock settings are lower than 450mV, right?
I suggest leaving them where you tuned with or
changing them slightly after wards too much will throw off AFR/LTFTs
Lower switch points=leaner
Higher switch points=richer

stevedarman
January 2nd, 2010, 08:54 PM
Good info thanks for that