My 98 V70 sat idle for 2 mos while I was out of town I went out to start it and it will crank over but will not start, well I first thought either fuel pump fuse , relay or pump in that order. Checked the fuse OK, replaced relay still won't start, next checked the pump, diconnected the connector checked for voltage nothing. I checked the pump with aux 12 volt power source pump runs fine. Checked the connectors for the relay no voltage with ignition on or when cranking, then I checked the fuse connectors again no voltage. Now I'm out of ideas, anybody have this problem or know what to check next, I don't have a wiring diagram to trace back to the next piece of the puzzle.

 

Sounds like fuel pump relay is bad. Did you try bypassing it?

If it runs when bypassing relay but then doesn't when you replace relay, then either relay is bad or ECM is not signaling relay to turn on. Do you have a scanner by chance?