I have some pretty bad bucking at 1600 RPM and only with VERY light throttle. If I accelerate through 1600 RPM, there's no bucking and if my foots off the accelerator at 1600 RPM there is no bucking. I have roadrunner and have tried changing base spark, high/low octane spark, desired airflow, TC, VE table in this area (1600 RPM and around .2 g/cyl). All with no effect. The logs do show about 10 degree timing swings when this happens. I tried logging every timing related PID and the numbers just don't add up either... Base spark or run spark with smoothing doesn't equal actual timing (all other PIDs were 0). I am attaching my tune and a log of this event. It was bucking pretty good at the end of the log (and a few times in the middle of the log). Anyone find something that works who has experienced these conditions?
Derrick
P.S. This is SD tune and no factory O2's.