Thanks, that is a logical answer that fits the problem like a glove. The car has 115K and is in really great shape in nealry every respect. But when I replaced the plug wires not long ago, they were pretty thread bare. I suspect the same might be true of the injectors. Unrelated, but similar in age, was the heat/AC blower when I recently relplaced the original blower regulator -- with help from this forum, by the way.

Question: How can I tell if the injectors are worn? How difficult to replace?

Thanks for a great response.