Engine surge and fluttering while cruising.
 

I was pulling a bobcat this week on the highway. Noticed that my truck was jumping about 50-100 rpms while on the lower range of the high gear. I have a quadzilla on it and a fass pump. It's staying around 10-14 psi after the filter of fuel pressure. Has 174,000 on it and all original parts from what I can tell. It's been starting and dying the first time it's cranked in the morning. I have figured just the cold weather. Anyone have any ideas. Crank sensor was changed two years ago. Also have a superchips flashpaq on it. Superchips programmer is set to performance and the tranny has a ats valve body.

Mine would do that when my torque converter was failing. stopped doing it after i put in the new one, just a thought

I'm not 100% sure but I think the superchip adjusts timing on each tune. So running it and your quadzilla together could be the problem.

I thought about the two running together might cause the issue. When I watch the quad gauges on my phone it keeps good fuel pressure and the boost stays at a steady pressure. I really don't think its a motor performance issue. Was worried about injectors or injector pump issues.