Update on wet wx stalling...
I found after much frustration, that the ignition wire from the coil to the distributor cap was arcing way down near the crimped connection in the wire cap at the end that plugs into the distro!

I had kept the ORIGNIAL wire from my 91 wagon in the trunk as an emergency spare and I popped that in last time it happened (last week!!) and voila no more problems..that's when I took a closer look...the 91 wire has an inuslated
centre conductor over the length of the centre pin except for a portion about
1/4 inch back from the end....the NEWER ones from Volvo DON'T have the insulated centre pin, in fact they have a fat centre pin that is exposed the full lenght...

This was a NEW wire, so I took a look at the older one that had been on the car for 4 years and wouldn't you know it had arcing in the same place!

I pulled the distro cap off and checked it, but couldn't see any cracks or tracks
but changed it anyway, put another NEW wire on, but greased the boot with dielectric grease. And so far, the car's idle is spot on, and no stumbling or
loss of power...but then it isn't raining here in Toronto today...

Check that wire with a good light and magnifying glass if you see grey
ash on the centre pin down just above where the wire is crimped to the
connector, there's your problem.

Dans