Hi guys i have a small issue with my engine

I noticed these engines act differently when cold for starters compared to the 08 353 i have, the issue im having is that in yesterdays A final it would stall straight after a pit stop. it sounded like it went rich and just died. temps were around the 125 degrees celsius mark.

apart from the stalling it was fine. im thinking it could be a rich bottom end? or maybe a longer pressure is required? could it also be that im using a pressure chamber on the fuel line for more fuel volume?

Thanks
John G