I have noticed several early morning start ups with annoying episodes of 10 seconds or so of engine missing. Sounds like rich running missing? I have become aware that missing don't always occur, only occuring on mornings when the car had been cold started and pulled it into the garage the night before. Car only allowed to run less than a minute when pulled into garage for the night. (not long enough to warm up).

My early theory is that the enrichment for the morning start is somehow being enriched TOO MUCH due to the cold start (but no warm up) 7 to 8 hours earlier when the car was put away in the garage for the night.
Does the enrichment start off with a base of wherever it LAST RAN ?
It is summer here now, 60F at night, but similar episodes have happened even when nightime temps were lower this past spring.

Anyone else have an idea?
70K miles, Car runs fine and does not show no other signs of trouble.
OK mileage (aggressive city use=16mpg; Highway, 70-80 mph cruise= 21mpg-22 w/o air)

DanielW