Post by
float_6969 »
https://forums.nicoclub.com/float-6969-u780.html
Sun Apr 27, 2014 5:13 am
Sounds like weak spark. Turn the boost down and see if it goes away. It could also be because you're crazy rich. There is no reason to ever see anything less than 11:1 AFR's unless you're knocking and so the tuner dumped in fuel to deal with it. Still though, that can still be traced back to weak spark.
If turning the boost down fixes it, close the spark plug gap down some, turn the boost back up, and try again. It will probably be improved. If it is, but not solved, close the gap a little more. Don't close the gap too much, or you'll get incomplete combustion in the upper RPMS and it will lose power or break up again. You always want to run as much spark gap as you can without the spark breaking up.