Hi Bill,
Just a note, you are better off not having your AFR's set to 12.95 below 800 RPM, reason being, is if the engine ever stalls, MAP will go to 90 - 100kPa and the PCM will throw a bunch of fuel in (not so good).
As for the KR, is it happening at one spot only?, what are the actual AFR's at that point and timing?
12.95:1 AFR is about as high as I would go, I run my car at 12:3:1AFR, it's not on the edge and allows a bit of safety in hotter weather. Many would dispute that I am losing power by doing this, possibly, but I am not at the strip everyday, so if I am losing 10 - 15Hp by running a touch richer on the street I am not worried.
I found (on a dyno) the power difference between 25deg timing and 28 was very small, which tells me the motor does not want more than 25 anyway, so that is what I am running.
So in summary, my street tune I run mid 12 AFR's with about 25 timing.
As for the bad gas problem.......this might help.
http://www.flat-d.com/
Cheers,
Ross
BTW, your post only showed up on my PC this morning :?