Stumble after coasting Dodge Ram Van Wagon 1500 1999

dodge
acceleration
wagon
ram
misfire

#1

We drive a 1999 Dodge Ram Van Wagone 1500 1999 with 5.2 motor. We drive it a lot on long trips like to Alaska and tow a large boat. It has 180,000 miles and is kept in top running condition.



on a recent winter trip to Montana it had a new issue.



After a prolonged coast at closed throttle, such as a long downhill or coasting to a stoplight from speed, the engine would misfire for about 1 to 2 seconds and then run normally.



Now that the air temperatures are above freezing the problem has gone away.



Any one else got an idea??