The Top DSM Community on the Web

For 1990-1999 Mitsubishi Eclipse, Eagle Talon, Plymouth Laser, and Galant VR-4 Owners. Log in to remove most ads.

Please Support RTM Racing
Please Support Morrison Fabrication

SAFC newb question

This site may earn a commission from merchant
affiliate links, including eBay, Amazon, and others.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

crashed97tsi

20+ Year Contributor
829
0
Apr 21, 2002
Bethlehem, Pennsylvania
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
 
Damn if this is a Newb ? then i would hate to see an Advanced ?. :p
 
I just figured by the other stuff in the tuning section that this was newbie. If it's in the wrong forum I apologize :)
 
No not wrong forum but it just looks and sounds advanced.
 
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.
 
Support Vendors who Support the DSM Community
Boosted Fabrication ECM Tuning ExtremePSI Fuel Injector Clinic Innovation Products Jacks Transmissions JNZ Tuning Kiggly Racing Morrison Fabrications MyMitsubishiStore.com RixRacing RockAuto RTM Racing STM Tuned

Latest posts

Build Thread Updates

Vendor Updates

Latest Classifieds

Back
Top