Hi guys, totally new here. i have a 2015 5500. i bought it deleted, studded, tuned with RACEME Ultra, BBI stg 1.5 injectors. it is about to turn 80k miles, i have put 7k of those on it. i pull very heavy so i run on the 30hp tune. i installed a FASS titanium 165 in the last 1500 miles with a FASS sump and top draw kit at first. The pump made a lot of noise and the truck was running worse than before but with less smoke. i ran the tank low and switched to drawing fuel on the bottom directly at the sump. The truck runs much better and reduced the smoke more. My problem is now it seems to have a miss or knock intermittently only off idle. it doesn't do it any other time that i have noticed, only from a stop after idling, like at a stop sign or light. if i throttle slow and easy, it is normal and smokeless. if i have waited at idle and try to take off anything moderate to floored it falls flat on its face, makes a distinct knock, it sounds like a single miss fire but all power hesitates while blowing a solid black puff and then proceeds to accelerate as desired. Anyone have any similar scenarios? Haven't had the truck looked at, the Fass is the only mod i have performed besides a mechanical boost gauge. Not throwing codes or CEL, does it empty and loaded/towing