Hiya...
Its not the fuel pump as its in the tank directly behind the rear seats.. Only suggestion i can tell you about the pump that if the car is left parked up for a long while and no petrol in it the pump will rust up with the condensation in the tank... However good news is that u can take the pump apart and put it back together again with a bit of work... It a high pressure pump so watch if your taking it out...
It a complete nightmare to get at the pump mind u...
With thanks