SAFC newb question

[crashed97tsi]

Hey guys,

Well, I just got my injectors put in and I'm trying to adjust the Fuel trims again. I think I got it down but there is something that is confusing me. The STFT is the reading the ecu is getting from the O2 sensor and the LTFT is just a long term reading from the O2 sensor. Is that correct?

Ok, now say you have a +5% LTFT and a -2% STFT. That would mean that the ecu wants +3% more fuel right? Right now, after a nice hour long drive my LTFT is reading +5% in most of the rpm ranges. I should add some fuel to the SAFC so I can try and get rid of that right?

I tried searching but I never quite figued it out. Some people sayjust tune by the LTFT, others say add the 2 together. I would just like to know what people have found to work the best.

Thanks

 

[TurBoGs-T]

Damn if this is a Newb ? then i would hate to see an Advanced ?.

 

[crashed97tsi]

I just figured by the other stuff in the tuning section that this was newbie. If it's in the wrong forum I apologize

 

[TurBoGs-T]

No not wrong forum but it just looks and sounds advanced.

 

[Coldandafraid]

the STFT is the O2 sensor correction. The LTFT is the ecu's memory of what you need at that specific RPM.

And, you are right, +5 LTFT and -2 STFT means that you are needing 3% more fuel at that RPM. So, add 1 or 2% on the AFC and eventually that RPM will even out to 0% LTFT and 0% STFT.

 

[crashed97tsi]

thanks