Thanks in advance for all your help!

My 1982 245 wagon (B21, NA, K-jet injection) has died mysteriously several times recently. I'm sure there may be some common circumstances to these events, but I haven't discovered what they are yet. There have been no recent repairs that might be suspect, and the car has not been unusually wet, hot, or cold. Plenty of gas in the tank. Here's the brief history:

It died suddenly while cruising along the highway but I was able to restart it almost immediately. Later that same evening, it drove without incident and then would not start after being parked for about 30 minutes. Ordinarily, this car starts right up. It did start after about ten more minutes of rest.

While the car was "resting," I checked the fuel pump fuses and swapped in my spare fuel pump relay, just in case. I say "just in case" because although the car wouldn't start I could hear the fuel pumps run without unusual noise when tested, and the car would still not start while bypassing the fuel pump relay with a jumper wire at the fuse block.

When it died while under way it died suddenly, without the momentary rough struggle you might have with fuel starvation. The fuel system had a thorough work-over about 40K miles ago.

What do you think?