At the first sign of a fuel pump that has started to play up, the advice is to replace it as soon as you can. These electric pumps can start to have intermittent faults where they will not pump fast enough or not at all, and then the next time you start the car, they'll work perfectly. Don't be fooled into thinking it's all okay, however, as the pump will progressively get worse and worse until it won't work at all. Trust us, these things do not fix themselves. And since a fuel pump will leave a modern fuel-injected car absolutely high and dry, you're way better off fixing it now (by replacing the pump) than finding yourself stuck on the side of the road in the middle of nowhere.