I have a 1998 Ford Explorer with really low miles (< 30,000 miles; classic "little old lady who only drove it to the grocery store once a week" type vehicle).
The first time I start it on cold mornings, while idling the engine will rev up to somewhat high RPM's for idling, sputter for a few seconds, rev up again, sputter for a few more seconds, etc. The engine may even die during one of the sputtering phases. The sputtering is worse the colder the weather is in the morning.
Once the car warms up, it idles and runs fine.
Any hints as to what's going on with it?