Start then stop
 

My 2006 S60 has 142000 miles on it, and sometimes when I start it, it will appear to want to start but it won't stay started. I've already had the radio module replaced for the starter.

did you try jumpering the fuel pump relay? test the fuel pressure - sounds like you may have a fuel delivery issue or a problem with the pressure sensor. Any fault codes?

No, I have not tried jumpering the fuel pump relay. No warnings on the dash, fuel pressure sensor has been replaced before, acceleration is normal.