It is desert season again and again same problem. Nothing has changed since my last post. I watched closely and everything is as described in this post. The RPMs that this happens at vary, the EGTs that this happens at varies. I never hit 2700 RPMs on the pull.
The consistencies that I notice are that it doesn't do it until into a hard pull for a while, the boost drops suddenly and then jumps back up just as suddenly, the rpms don't change except when the speed drops maybe two mph when the boost drops, the EGTs drop by two to three hundred degrees and then comes back up when the boost increases. It seems to defuel about every 30-45 seconds.

This is driving me nuts. I can't figure it out.

Any more suggestions?