I think Spook, Steve, and Ken have covered most of the topics. But I'll offer another suggestion as well as a couple tests that have worked for me.

I've experienced pump problems 3 times on my 1995 940 Wagon (8-Valve)

First was sudden pump failure around 180k. The Other two were the hose popping off the pump.

Anyway, I confirmed a failed pump by accessing the pump/sender pigtail in the driver's rear quarter panel space.

Identifying ground and hot (usually red and black the other two grey or green wires are your fuel sender resistor wires) I applied 12v power from a portable charger and couldn't hear the pump running.

You did a similar test by switching the ignition to KPII and listened for the quick hum.

Anyway, if you get nothing the pump is probably dead.

If you hear something like a fishtank waterfall inside the tank, your fuel pump hose has come off.

That sucks, but it is a straightforward fix. I've had to fix that problem twice. Aftermarket FI hose doesn't fit well...

Anyway, if you hear the pump running and don't hear a waterfall inside the tank, then the problem may be your fuel filter.

Quickest check I know is to take a 14mm and 17mm wrench and carefully loosen the fuel line fitting up on the fuel rail. Once free, put the fuel line into a small (DOT-Approved) container and go back and crank the engine for a bit. Check the container.

If there's a lot of fuel in there, fuel is probably not your problem.
If it's pretty much empty, then your system is clogged somewhere between the pump and the rail (i.e. filter)