Hey everyone,
I've been playing with some ethanol on a very basic flex tune I made. Nothing wild, just enabled flex and then upped the base timing. It was running great, on the first fill, and the second fill, but on the third full fill of e85 I started throwing random misfire codes, and at one point got a flashing MIL from a transient but heavy Cylinder 2 dead miss. I believe that it was triggered by finally reaching full flex fuel ethanol concentration. I burned the tank halfway down and filled with premium and it has gone back to normal. However I don't know what I'm doing wrong, I've uploaded the files here. One uses stock gasoline timing, and the other steals some timing from the F150 but with a neutered multiplier. Both maintain stock gasoline MBT tables.
02_2019 mustang gt_stock_timing_flex.hpt
13_60percent_full_pull_2_070223.hpl
13_60percent_full_pull_070223.hpl
13_2019 mustang gt_f150_timing_flex.hpt
If anyone would be willing to briefly look at any of these files I'd appreciate any insight greatly. My guess right now is that my target lambda is off causing too rich of a mixture, but I'm not 100% sure. I've used the 02_ file before but never with more than 50% ethanol, and it worked fine.