Hello,

I have an 05 Evo on e85, full tune, cams, the whole 9 besides upgrading the turbo.

I go out of town quite a bit at lenghty amounts of time (3-5 weeks), and the car gets started every 2-3 days or so while I'm gone.

2 week ago when I got home, I noticed the idle went from 15.5ish AFR down to 14.5ish AFR.

This time I just got home and drove it and noticed its now idling at 13.5ish-14.0.

Starts fine, runs fine, boosts fine, no issues there what so ever. Just running way richer at idle.

Plugs are only about 2k miles old, using NGK coppers, with Spoolin Up COP, 950cc injectors, 255 walboro.

Ideas what would be causing this? Would like to address is before I leave again.

Thank you!

 

Hah, I'm not very informative on E85, but in winter my Evo would idle around 13.5afr and now that it's summer, she idles at 10.5 or even lower on 91oct when warm. I wouldn't worry too much since its rich and not lean. Not sure if yours could be due to weather/climate change. I'm sure someone with more knowledge would chime in :P

 

Can you post up a log of idle when car is warmed up? Log LTFT LOW, o2 feedback and AFR.

 

Check for boost leaks, but you might need to adjust the compensation tables depending on when the car was tuned during the year. Ex: if it was tuned during the colder months, idle characteristics could be thrown off a little bit during the warmer months because the AF mixture is not being compensated properly.