450sel Fuel system problem?
 

Nearly a year ago I had the fuel accumulator changed, which cured a rough start problem. Last week the rough start return, yesterday after turning the car over is tried to cut out, I gave it gas kept it alive. In the afternoon the car died! It seemed to not be getting enough gas when the pedal was pushed, this occured around 20mph, it was lagging, almost as if i was running out of gas, which was not the case. Now it wont turn over. Fuel pump? Fuel filter?

Thanks.