I would want to monitor the pressure when it is doing this. Also, are you 100% sure the fuel lines are not blocked or pinched anywhere? When the car acts up try removing the gas cap and see if it pushes air out. This would indicate that the tank vent is not working or the line between it and the charcoal canister is pinched/melted/collapsed. Just trying to give some ideas for fuel flow issues.
I will say that if you do not have an adjustable fuel pressure regulator they are nice to have.
I will say that if you do not have an adjustable fuel pressure regulator they are nice to have.