C6 LS3 tune LTFT - STFT
Thread Starter
Cruising
Joined: Dec 2020
Posts: 14
Likes: 1
From: FL
C6 LS3 tune LTFT - STFT
Hi
Does the PCM compensate Fuel trim @ WOT ? My very little understanding is that it does till about around 48% throttle and @ WOT it uses the last LTFT so it could actually end up rich or lean is this true ?
Also is there a easy why to know if the tune is off by looking at STFT and LTFT? @ wot I am seeing LTFT1 -3.9 LTFT2 -5.5 pulling fuel , so I am guessing its off quite a bit.
Thanks
Does the PCM compensate Fuel trim @ WOT ? My very little understanding is that it does till about around 48% throttle and @ WOT it uses the last LTFT so it could actually end up rich or lean is this true ?
Also is there a easy why to know if the tune is off by looking at STFT and LTFT? @ wot I am seeing LTFT1 -3.9 LTFT2 -5.5 pulling fuel , so I am guessing its off quite a bit.
Thanks
Safety Car
Joined: Nov 2007
Posts: 4,436
Likes: 875
From: Bay Area CA
Only, positive LTFT will carry over to open loop (WOT) and can make for a richer condition. Negative LTFT Do Not carry over to WOT. So, if you are seeing negative LTFT going into WOT, the ECM is not pulling fuel when in open loop. This could lead to a lean condition. Ideally, + or - 5% LTFT is your target.
Last edited by Mike's LS3; Dec 19, 2020 at 12:51 PM.
