Ok, watched this on youtube also..So, the engine did stall out on its own from WOT, wasn’t sure when I watched the first time….
Could be anything…I wish you had an assistant with you for the ride so they could have pumped the fuel bulb when it started to crap out…
The loose fitting is a good place to start….
Just cuz the fuel pump is new, doesn’t mean it is any good….But usually they crap out at lower speeds…
Keep us posted….