Volvo Repair: 940 fuel pump, regina system, tank fuel

Question
I have a 93 940 sedan non turbo.  The in-tank fuel pump stopped working
the other day while parked overnight -  it was about 20 degrees fahrenheit
that night.
After awhile, I determined it wasn't getting fuel, and there was power going
to the pump,  but it just didn't do anything.  I used a hammer and a piece of
wood to slowly turn and remove the large retaining screw on the tank.   When
it was loosened, I tried the key one more time, and it pumped a little and then
stopped.
I thought, great, the pump's  not the problem!   I put it back together and it
didn't work again, so I figured maybe it was the banging on the bolt that
loosened something. So, I whacked the retaining screw a couple of times and
then, the pump worked again, and the car actually started.  Do you think
there was ice in the pump that kept it from pumping or do you think it's just
bad?  (I haven't had any trouble with ice or condensation before. ) If you do
think I should replace the pump, do you have any tips on extraction of the
present one?  It's a tight work space. Thanks for your help.   Frank B

Answer
Frank, put it this way, They SUCK.  Once those pumps decide to fail they just fail.  Im assuming you have a regina system with only one fuel pump.  If you have a bosch system, you would have a main pump and then  intank prepump.  The tricky part is getting the unit out without dropping the large o-ring into the tank.  The large fill hose needs to be moved out of the way with your left hand while you are moving the unit with your left.  It basically twist here and there and when you put it back in, it must drop into the baffle or it will not work properly.  Personally, to keep your sanity, I would have a Volvo shop perform the work but thats up to you.  Roger