first citroen

I have recently bought a Citroen 2003 53 reg C3 1.4 16 valve HDI which was running really well then without notice it misfired once and cut about a mile later and would not restart, the AA man connected his code reader cleared all of the faults and carried out a live parameter check which showed low fuel rail pressure, before i spend a fortune on a new fuel pump does anyone have any ideas that i can try, many thanks Pete