Hiyo.

I wish I could say "it's obviously a blah blah blah" but I can't.

My suggestion is to read through the FAQ and see if anything pops out at you. Maybe you could make a list first of all the things that you notice.

When you push the gas down, does it hesitate, then increase engine speed? Or does it start accelerating immediately, then slowly bog down as it approaches 2000?

The best thing you can do is to document the heck out of everything the next time the issue occurs. Noises and such first, then things like the weather, if the car's warmed up, how long since it had been driven before that. Let it run for a while. It's not going to blow up from running rich or lean, and if it finally stalls out and won't restart, then you have a "non-intermittent" problem ;)
Listen under the hood and note any noises you hear. It's a 940, so you should be able to check the fuel pressure at the rail through the schrader valve. Don't use a tire pressure gauge, there must be a specific gauge.

You can also probe the O2 sensor with the car limping along and see if the voltage is stuck on one side or other of its range.

You can also -I know this is safe for the LH2.4 models, I ASSUME it is safe for the 3.1 version or whatever they used in a 94 940- unplug the AMM and see if the car improves. If it runs better (through the whole power band) then that means the AMM is probably bad.

You should also check for vacuum leaks, though I can't think of anything that would stick in cold weather.

The engine coolant sensor comes to mind - there are 2 of them. You can check to see if it is in the right Ohm range and also to see if the wiring is intact. I believe it's in the runner near the car's firewall.

Then, compare all these values (write them down) to the car when it's acting normally. That should give you a good starting place to track down the issue. If it frequently happens on moist/rainy days, it could be a cracked distributor cap or some kind of wiring short.

Good Luck!

Then compare all these