W126 Intermittent Stalling Problem

[raymr]

My car has a history of the occasional stalling problem, where it starts right back up again. But in the last month or so, it's been different. Three times so far, it would stall and then not start for at least a minute. Then once it starts, it's perfectly fine again. Normally the engine runs with hardly a miss, no smoke, and decent power. Idle is 700/550.

This has me a little spooked now, as it did it again today while pulling into my driveway. It usually happens while slowing down or stopping, but one time it acted the same while trying to start it hot in a parking lot. Not knowing better, I would describe the symptom as very temporary vapor lock.

This is the worst problem to diagnose because it's intermittent. Has anyone had this problem and figured out the cause?