1991 240 wagon stalled at red light while driving in heave traffic in 100 degree heat. Symptoms mimic vapor lock. Towed to garage, sat overnight. Started right up this am and has been running fine since.

Fuel pump relay? Or?

 

Was the engine over-heating?
With normal engine temperature, these problems are rare.
A defective fan-clutch could be the culprit.
That it happened at a red-light - further points towards the fan-clutch....

Christian

 

The engine was not overheating.

With ambient temps over 100 I'm leaning onward vapor lock, especially since the car runs fine now (fingers crossed). Still, I ordered a fuel pump relay from IPD.