new to tuning, help w/ LTFT's
 

I'm new to tuning and have found the :hail: people on this site to be an extermely valuble asset in learning the process. That being said, I have one question: How many times do you usually have to adjust the VE tables to get the LTFT's right? I set the MAF fail frequency to 0 and selected re-set fuel trims, but everytime I get close and try to tweak a little I get way off again. Any suggestions or input would be appreciated! I was trying to get all squared away for the first EFI race of the season at E-Town on Saturday.

I am in the same boat that you are. But are you letting the computer relearn the LTFT after you input all the values and the changes you made. I think you have to give it time to learn and then start tuning it once again. At least that is what I am doing.

i got VE's pretty much nailed down in 2 sessions, and that's with narrowband. I do have a slightly different approaches to 'teaching' the pcm, i don't just go drive 50-100 miles like most suggest, i go drive that but in smaller chunks, so there's time for cooldown/warmup, and few full cycles. seems to make it stabilize fairly quickly.

2 sessions with my wideband and the VE table was nailed. 1 session more and my MAF was nailed down too.

Which way does it go way off? in the other direction?
If so, then maybe you're making too big of changes at a time.
I would also give it more time between changes to let the LTFTs stabilize more.

Try disabling LTFTs (forget which tab it's under offhand) and use the STFTs ... make sure the histogram is averaging also (right click on it, select average)

VE tuning and stock narrowband works great (since the O2 sensors are very accurate at 14.7:1 AFR)

Also keep in mind you may not be able to get everything to 0... I shoot for 0 to -4

Also keep in mind that if there is significant change in the weather that will cause a definite change in the PCM VE adjustment.
In short, try and do the tuning on days where the temp and humidity is similar to the last time you made a change.

:usa: