I may be able to help you and it can be very simple. My 1993 960 had starting problems, that is, the starter worked but no ignition and probably the fuel pump didn't work either. The ESW transmission light flashed so I thought I had the PHP? switch problem that is mentioned on the Web. But sometimes it fired off as if nothing was wrong.
Two Volvo dealers had no idea. I checked the usual like the groung wire connected to the left (driver side) motor mount. While checking from above I moved a black cable and I heard a whinning noise that is the injectors or something (the start key was on.) The noise is normal because I jumped into the car and it started!
I followed the cable and it connects to a relay. The connection was loose, that is, the connection is under the relay and gravity pulled against the connection. Let me describe where the relay is located.
Stand in front of the car with the hood up. On the drivers side lean over and touch the black terminal box that sits on the side of the wheel well. Just to the right (as you stand) are two gray relays. They are just in front of the shock/strut tower. Make sure the connections are not loose.
Also remember that 75% of all faults you can see or hear.
William.