I dont think the wires would be corroded as the contacts are under little rubber covers, then the whole fuel pump is under another cover.

There seems to be a problem with the relay that controls the fuel pump. The solder joints can go bad causing intermitent problems. I did a quick search on Google and it seems Bosch relays often have this problem, on Volvos etc.

Unfortunaltly on my car the relay is behind the ECU and ABS computers which are in turn behind the battery, so not easy to get at! Should be easy to repair though.