Problem understanding my logger...

[my98gsx]

i just got a logger for my car to tune my air fuel because i recently put in 650cc injectors and needed somthing to tune off of. What i have on my screen reads "short term fuel trim" and "long term fuel trim"... the long term reads "6" or "7" and stays there with VERY little movement if any... The Short term does move especially on a stong pull, and goes from "0" into + and - numbers. What i got from looking into things and talking to people is that the "+" numbers show when the car is LEAN and the "-" numbers show the correction value of the computor which means that the cars running RICH... The more and more I retard my AFC the lower the "-" numbers are under a load... I was wondering if anyone knew what number i want to really get my car set on... i feel that ZERO means that the car does not meed to compensate for anything ( on idol i got the car to run from -3 to 1 so i think thats the range where i want my car to be under a strong pull ) If anyone has any ideas please let me kno... and if there is a spicific way of tuning ( weither u just do a 3rd gear pull ect...ect?) im new to this logger stuff, and have no dsm people to talk to about using it. Thannks.

 

[MyBeatGSX]

According to the tech article on this site, you want the average of the high and low to be as close to zero as possible. Having them actually both at 0 would be nice to, I was able to get most of mine there.

Keep in mind, tuning fuel trims is for light throttle cruise only. You shouldn't be concerned with where they're at or what they're doing during strong pull, they have nothing to do with that. They're just showing what the ECU is doing in open loop mode. In closed loop, like during a WOT pull, they're completely disregarded.