2003 Rover 25 difficulty starting

I recently bought a Rover 25 in Nottingham and drove it to London, where I live. It was fine on that journey. Then I went to go shopping and there was a strong smell of petrol so I checked under the car. It was leaking all over the ground so I contacted Green Flag. They took me to my garage nearby and apparently it was my fuel injector pipe that had broken and subsequently fallen out. This was replaced with a new one.
I then went to drive back to Nottingham after filling the car with petrol and the car was fine until I hit heavy traffic. She started to stall and the engine maintenance light came on the dashboard. It cut out totally and so I tried to start it again, it was fine until I put my foot on the accelerator and the revs started to dip low and cut out again. I drifted into "the lane" and stopped, I called Green Flag and they collected me and took me back to Nottingham.
The car then went to a local garage the next day and apparently it was a clogged fuel filter, which they changed. I then put it through a full service.
I recently collected it and drove back to London however now, every time I go to start the engine, it won't start immediately. It takes a coouple of tries before firing up. Does anyone have any suggestions on what's causing this? Also, the petrol pump in the tank is making a very loud noise but it no longer smells of petrol.
Please help!