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Lately my ltft is constantly going positive. Floats between .8-2.3%. After making the adjustments it will go to zero, but then the next time out its back to 2.3...
I checked for leaks and didnt find anything. Only thing I didnt check were for any exhaust leaks, but idk if that would mess with the fuel trims? Any ideas of what could be causing this? My only thought as of now is the gas Im mixing, E47?
Mods are K&N intake, Dejon upper cp, meth kit, zzp catless dp, E47 tune.
As the E content in E85 decreases to 70% for winter blends, your fuel trims should go negative, too early for that IMO. The exhaust leak would have to be pre top O2 sensor or shortly after to affect it and any small leak would cause a much larger shift. I think if you drive it a few long trips it'll settle out, takes more than one drive cycle. My LNF was happiest at +0.8 LTFT, would never stay at zero. I think it's the nature of the LTFT algorithm but never found proof.
If you blew the mix by 5-7% over it'll shift ~2% on the trims. No big deal as the LNF uses the WB even at WOT to compensate, much better than the LSx open loop WOT I live with.
lnf motors have been blowing out the turbo gasket that mates to the exhaust manifold. if you have a small flexible and extendable mirror (found at most parts stores) you can check the gasket condition with just the mirror a flashlight and a floor jack with stands. your not necessarily looking for the gap at the gasket but burn marks or black soot marks straight out from where the flanges meet.
24 psi runs cause enough heat at 16* timing to stretch the turbine mounting studs and cause leaks.
All gaskets look clean. I am going to replace the dp to catback gasket tho. doesnt look in to good of shape. But i dont think that would cause the issue. I think it was the mixture of fuel I put in. The last time I filled up I wasnt paying attention and put a gallon more of 93 in, now I filled up even so that probably was it. Ill let you guys know if it changes on me again due to the mixture lol