doesn't help with your problem but just to clear this up a bit - the fuel pump does not cut out when it has pressurised. when you key on it is on a timer as part of the program in the chip. when the engine is running, the pump will run continuously. there is no pressure sensor anywhere on the fuel system, unlike the abs unit as tabetha has advised

the abs has a separate loom with a couple of relays, but i would have thought that if they are the problem then the pump would not run, rather than run constantly