Your 380 SL acts like it is running out of gas When you top the tank off it runs good for about 80 miles but then acts like it is out of fuel Is it the fuel filter or the fuel pump?

I'm not sure what you mean by acts like it is running out of gas....a car runs fine until it runs out of gas...at which point it stops and won't start again until you put gas in. There is no difference in the way it acts on the first or last drop.