engine reving up about 100 rpm on its own at idle

[azcummins]

My 98. 5 24V will rev itself up about 100rpms when you shift out of a gear and come back to idle. (Like coasting to a red light). It will do it 2-3 times, then the engine just idles @ 800rpm.



I think there is a TSB out on this, but I didn't see on on the TDR TSB listing for my year. Anybody know about this?

 

[TomGolden]

I am not sure about a TSB for it, but my ETH motor does a similar thing. On some mornings, doesn't even have to be cold, when I'm coasting down my driveway and steet to the stop sign on the main road about 200 yards from my house, the engine will suddenly idle up on its own to 900 RPM, then when I hit the brakes at the stop sign, it goes back to normal idle speed. I have only noticed this behavior when first starting out in the morning, and only on my street, as I am uphill and almost always just coast down the hill to that first stop sign. It also doesn't do this every day, maybe once a week.



Tom