Loss of power when hard accelerating with less than 1/4 tank of gas in tank. Could this be the fuel pump relay or the in tank prepump?

I sometimes hear a CLICK from somewhere in front of me when accelerating and then I experience a slight hesitation but now independent of whether this happens, I'm experiencing sporadic power losses when gas tank is low.

Thanks,

Ruben
240 1991
87,000 miles

It's rather surprising to find this in a car as new as yours, but I've heard that it's more apt to happen if you've used gasohol (gas and alcohol, or gas and MBTE) mixtures. I've only had it happen on two cars that were almost 20 years old.
Anyway, you've got a leak (a split, usually) in a short piece of rubber hose (the rubber doesn't like the alcohol) between the in-tank pre-pump and the metal fuel line. When the fuel level drops below the crack, you will start to lose fuel flow (it's squirting out of the crack), whereas when the fuel covered it, the surrounding pressure kept the fuel inside better. [some say that air is being sucked into the line, but the pre-pump should be keeping the inside of the hose at a higher pressure, so I don't buy it.]
And you have only one solution -- you have to open your fuel tank and pull out the pre-pump and fuel gauge sendor assembly, and replace the hose. It's also a great time to change the pre-pump and the sock or strainer at the bottom, too (chalk it up to preventive maintenance). And use two good clamps on the hose ends -- Volvo tends to be "cheap" in this area.
Finally, viz. the "sparking" possibilities that the others have mentioned, remember that it is possible to buy the special wrench (for the gas tank cover plate) from your Volvo dealer (and it isn't too expensive) -- it makes the job a breeze!
Good luck.

THANK you all very much. I'll do it this weekend and hopefully not explode in the process!

When I did mine, I went ahead and forked out the dough for the IPD special tool to access the in-tank pump. I thought it was very expensive for what it is, but it worked very well. It was also great to have when we did the same job on my son's car. Good luck. Lots of people have found that the little hose in the tank causes the symptoms you describe. It's not a difficult job. Just be careful around all that gas. Have lots of ventilation, etc. No sparks.
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Thanks to everyone for the help, Doug C. 81 242 Brick Off Blocks, stock, M46; 86 240, 133k

Ive had that problem with a 240 I owned a while back. The problem is not major. In your gas tank is a secondary fuel pump. It has a metal fuel line running to it but is connected up to the fuel line with a rubber fuel line. That rubber eventualy goes bad and causes the problem you are describing. On mine I never repaired it. I just drove the car with a mostly full tank. It seems like it would cause your fuel pump to work extra hard though so I would repair it.

You can get to your fuel pump inside the gas tank through your trunk. There is no need to drop your gas tank. The hardest part I had was turning a metal ring that ultimatly holds the pump in place. I beat mine with a hammer and screw driver, all the while wondering what would have happen if I made a big enough spark =)

Good luck,
Francis

"I beat mine with a hammer and screw driver, all the while wondering what would have happen if I made a big enough spark =) "
It is suggested that a none sparking tool, eg. brass be used. Can also flatten the end of some 1/2" copper pipe for similar effect.
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1980 245 Canadian B21A with SU carb and M46 trans