short term fuel trims
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TECH Veteran
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Joined: Nov 2003
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From: Tallahassee, FL
short term fuel trims Hey guys,
Quick question. I'm here looking at my s.t.f.t. and I have a bunch of negatives. Low negatives, mainly -2's and -3's. Negatives are adjusting for a lean or rich condition?
Why are some of the -3's highlighted in green?
Also, I'm trying to get everything zero'd out. For me, I'd want to go to my VE table and add negatives into the cells that are seeing negative stft's. Correct?
Thanks,
Kyle
Quick question. I'm here looking at my s.t.f.t. and I have a bunch of negatives. Low negatives, mainly -2's and -3's. Negatives are adjusting for a lean or rich condition?
Why are some of the -3's highlighted in green?
Also, I'm trying to get everything zero'd out. For me, I'd want to go to my VE table and add negatives into the cells that are seeing negative stft's. Correct?
Thanks,
Kyle
TECH Fanatic
Joined: Mar 2003
Posts: 1,839
Likes: 0
From: La Porte, TX
Kyle, that is correct you would add negatives to the negatives to get them closer to 0 and you would add positives to the positives to move them closer to 0. However if you are showing -2 to -3 then don't change a thing. That is right where you want to be. 
Work on getting rid of any + numbers. Also don't forget to look at your LTFT's as well once the car has had time to learn the new tune (about 35miles). You LTFT's will give you an idea of the big picture as it is an average of what the STFT's have been doing.
As for your first question; negative is adjusting for a rich condition by subtratcting fuel...hence the negative number
Work on getting rid of any + numbers. Also don't forget to look at your LTFT's as well once the car has had time to learn the new tune (about 35miles). You LTFT's will give you an idea of the big picture as it is an average of what the STFT's have been doing.As for your first question; negative is adjusting for a rich condition by subtratcting fuel...hence the negative number
