My 78 gtb has this nasty little habit usually after a long run but sometimes after only 10 minutes of popping,sputtering,almost like it is running out of gas. Just had distributors replaced,plugs,fuel pump,fuel filter,fusebox,etc.etc.etc. I am starting to wonder if it is something in the emission system as I have full factory emissions still in place. Car passed emission test at 30k service at Ferrari dealer in April.I am STUMPED. Magoo? Have no ideal what to try next.