Good question. I assume they can't make it quit, and all looks healthy in the doctor's office.

Taking care of the most common causes, tempered with economy, is the correct approach to an intermittent that won't show itself. Start with the 25A fuse holder and its red wire connections under the hood, and the fuel injection relay above the passenger's feet (as they did) and have them be sure the tank pump is operating. Finally, an inspection of the small wires to the Hall effect sensor (distributor) is worth the trouble.

Most try to say, if it happens again, watch to see if the tach needle moves when cranking. The idea is to divide the problem between spark and fuel. But (1) the tach may not respond to the low cranking rpm and (2) your car may not be equipped with a tachometer.
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Art Benstein near Baltimore

"I feel sorry for people who don't drink. When they wake up in the morning, that's as good as they're going to feel all day." -Frank Sinatra