Let's say I'm tuning with a stoich of 14.69, yet my fuel has up too 10 percent ethanol.
Let's say my ve table is dialed in for 14.69 using a wideband.
Now flip on fuel trims and it says I am lean.
Specifically stft.
Now let's say I retune that ve table with stft and it gives me an avg of 5% lean.
I add it in.
Now did I effectively burn my incorrect stoich value into my ve table?
So obviously the correct thing would be to either set the correct stoich point from the beginning then retune.
But what I don't get is how can you tune with narrow bands that are looking for a stoich point richer then the calibration's set stoich.
If I tuned with a wideband got 0 percent flipped on my stft and was 5 percent lean, then my stoich I should change by 5 percent and boom I should be 0 percent again.
If you don't change the stoich value and your stft keeps showing you 5 percent you would either ruin your part throttle ve work or it will burn in your stoich.
So what is the correct way?
Determine the exact fuel?
How ?
Up to 10% is just too undescript.