Volvo Repair: 1991 Volvo 740 fuel pump, fuel pump relay, volvo 740

Question
My Volvo has been stalling when I was driving so I thought maybe the fuel filter was bad. I replaced it and still had the problem so no I think it may be the fuel pump. If I understand correctly there are two in this model car, one in tank and one out of the tank. My questions are: 1)Can I replace the out of tank until I run the gas out to change the in-tank or will that damage the new pump. 2)I read that some Volvos have a hatch in the trunk to access the fuel tank does the '91 model? 3)Is there anything else I need to change or anything else that could be causing these problems? Thank you in advanced for any assistance you may be able to offer.

Answer
it depends what fuel system is in the car it may only have one pump.if it has a round coil it has 2 pumps if the coil is square  and on the drivers strut tower it has one pump in the tank.as for the 2 puump system I would start with the intank pump first.it may just be a bad fuel pump relay.