Quote:
Originally Posted by JvKintheUSA
Thanks Mod! Did a quick highway run and it seems that the coding on the Scangauge was incorrect. On the setting that you provided, I now read an A/F ration at WOT of 12.8 to 12, depending on RPM. Long term fuel trim stuck at 34 though..another issue I guess?!
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That's a relief! That's perfectly safe and not too far off from the likely best torque AFR (varies from motor to motor, but something around 13.2 is generally ideal N/A).
Congrats!
If you want to learn more about this stuff, I highly recommend you pick up the following text:
Amazon.com: Engine Management: Advanced Tuning (9781932494426): Greg Banish:…
It really spells out all of the basics with some clear information on more advanced topics. It will help clarify what the scanguage is telling you.
Also, regarding fuel trims, note that there are most likely multiple trims --one associated with each cell in the fueling map (which you probably can't access) or at least a block of adjacent cells; cells are graphed by load (based on MAF value and known engine displacement) and RPM.
Short term trims (based on vacilations around 14.68 AFR / narrow band .5 volts) are averaged to create long term trims. One of those is probably carried into open loop (can Modshack confirm or refute that?)
The LTFT of +34 may or may not be a cause for concern. So long as driveability is fine, AFR's in WOT are fine, and the CEL light is off, it's not ideal, but acceptable (ideally, you'd want to have th ecar tuned so that these are all in the single digits and driveability is excellent).
Man, I can't wait to start playing with uprev on this car
