A big problem on various mid 80's Volvos is the fuel pump relay itself. Solder joint cracks cause problems with the relay itself. The relay may engage but not pass the proper current and voltage. The solution on Volvos is to take the plastic cover off and resoler all the pins.
This may also work on your car. It's worth a try since there is no cost involved.
Currently 1965 220Sb, 2002 FORD Crown Vic Police Interceptor
Had 1965 220SEb, 1967 230S, 280SE 4.5, 300SE (W126), 420SEL
ENTER > = (HP RPN)
Not part of the in-crowd since 1952.