RPM drop and flutter when slowing down

[damsie101]

My '95 4.0L Ranger has had this problem intermittently for the past 2 years. When coasting to a stop or between downshifting to turn, the RPMs drop suddenly to below 500 and flutter between 500 and 1000 a couple times. Sometimes it just drops and stalls, quick enough that it will stall in the time between shifting from third to second. It only happens once the engine is warm and the weather is cold or cool and wet. This rarely happens during the summer months. I replaced the IAC valve last spring and the problem went away, but so did the cold weather. My mechanic replaced the PCV valve at the end of last winter, trying to source out the problem. It did little for the stalling problem, only improved the high idling that was going on. He thought its a vacuum problem.

Anyone else had this problem?

 

[eazyasone23]

sounds like when i had an intake manifold leak. my leak was only really affected when the truck was cold or if it was really cold over the winter. so you might want to check the manifold leak. are you throwing off any codes? u use usually get p0171 or p0174

 

[66427]

I had a Chevy 1500 that did that...turned out to be EGR valve...