My 2004 F350 "surges" then acts like it wants to shut off.This happens no matter what brand of fuel I use- name-brand such as Mobil or BP or off-brand such as MurphyUSA (@ Wal-Mart). I've changed both fuel filters & had a complete "go-over" done by a reputable fleet service dealer. It usually happens when I'm sitting @ a stop light waiting to go.It only happens after the truck has warmed up. Any suggestions?