I've had several Volvo fuel pumps fail me. The last one a 92 740 wagon took me by surprise. I was just finishing paying for a fill up and came back to a stalled Volvo. I fault traced it down to a lack of fuel and promptly jumped
the fuel pump relay to direct feed the fuel pump and went under the wagon to tap
on the main pump. To my dismay the only thing I found was the filter. The main and only fuel pump is located in the fuel cell. Mine had broken it's wires
and i got away with soldering them back together. It never as much as missed
prior to the failure. like I said I've had a series of fuel pumps fail and usually there's a warning ie. lack of power up mountains, missing under heavy acceleration. There's an inspection plate where the pump can be serviced from directly above the fuel cell. make sure it's not an electrical problem 1st.

Good luck