When reading my fuel trims, what should they look like. What do you guy's see when looking at yours??

Long term and short term.

 

I haven't used the ford software but when tuning LS1's you want the fuel trims to be in the negatives, between 0 and -5 is optimum. You do NOT want them to be positive (lean).

-Sly

 

Don,

Generally your short terms are going to be all over the place, they change constantly.

The longterms should be as close to 0 as possible. It also depends on the tune, the trucks will adapt to a tune over time. Anywhere between -15 and +15 is ok, closest to 0 is desired. At +25 is where you will see check engine lights for various reasons.

JimIII@JDM

 

Are the L's computers like the LS1's? What I mean by this is that on an FBody is the Ltrims are above zero (positive) then when you go to WOT the computer knew that you were last running lean thus it dumps extra fuel in and does not use the PE vs Main table (sorry ls1 table). Basically the computer has a reference table for WOT and it will not use it unless the LTrims are 0 or less at part throttle right before you hit WOT thus if the LTRIMS are positive you will run extremely rich under WOT. Then again the Ford computers might not be the same, someone correct me if I'm wrong please.

-Sly