I'm working on tuning VE using STFT and I wondered about the effects of the EVAP system on fuel trims. Right now, I'm disabling MAF, LTFT, DFCO, CFO and PE then logging the STFT in a histogram. I edit the VE "table", update the equations using EQ <> VE and repeat.
I think I'm on the right track, but I got to thinking about the LTFT cells and how cells 21-36 were used when EVAP was closed. Most of time the cells I see are 0-15 (EVAP open), which could mean that a little bit of fuel vapor is being added. Would this matter as far as using STFT to tune VE?
I don't think it would matter much but eliminating another variable might help reduce the number of iterations to get VE sorted out. Does anyone do anything about this or am I just crazy? I started looking at the differences between the histograms if I added filters for the fuel cells but wanted to know if I should just let them average out.
Thanks.