97 Miata 1.8 with MKturbo, ms3pnppro, 640cc ff injectors.

I had the VE table and afr table tuned really well and was.going good, but recently the afrs have been creeping up and I don't know why. I haven't changed anything. It still runs perfect afrs under boost but when I come down from a pull or just coming down to cruise after accelerating the afr will creep up to 16.2ish while cruising like 3k rpm 45-70kpa. I have tried raising the VE table numbers in that range and it doesn't help. Other conditions its perfect.

Any ideas? I can post a log tomorrow when I can get my laptop.

 

Is the atmosphere different fright now compared to when you tuned it? Things such as barometric pressure or ambient temperature can change the overall VE and there are tables in tunerstudio to compensate for that.

 

Log and tune. Always. This is the sort of question that a knowledgeable person may be able to accurately answer in seconds with a good log. Without that information all we have is your description which will lead to guesses and wasted time.

 

At lean cruise there is a relationship between the requested afr, ignition advance and the spark plug gap. If these are not correct you will have a lean misfire which shows as a high afr.