MicroSquirt.com read only forum (Jan.15,2018)

Yes your AFR is definitely jumping around when it's idling... And according to that datalog, there is no O2 correction going on... That's weird... I'm at a loss... But someone else, I'm sure, will be able to look at this datalog and give you some suggestions...

Obviously it is squirting while cranking, because when you disconnect the MS computer, it runs on the remaining fuel in the intake -- that fuel must've been squirted in there while you were cranking, right?

So, we can assume that "flood-clear mode" is NOT engaged, since it does appear that you're ...

A cam with a high-lift or long-duration can also cause fluctuating MAP values...

My camshaft has 0.515" lift and 275-degrees duration on the intake, and 0.541" lift and 285-degrees duration on the exhaust. My MAP reading constantly (and seemingly randomly) fluctuates from 43 kPa to 50 kPa at idle ...

While the car is ideling. the a/f starts slowly goes lean until the car almost dies, then comes right back, and starts going lean again

Sounds to me like your O2 correction is coming on while the car is at idle -- turn off O2 correction and see if that fixes the problem. When O2 correction ...