Hello All,
New to the board, first post!

When I come to a stop in my '87 740 wagon with M46 trans, the rpm first goes down (as it should) to idle at 750rpm... then the rpm jumps to 1500rpm quickly, and you can hear the engine revving. If you are in gear, it accelerates. It slowly settles back down to idle, but there is a noticeable jump, especially when pressing the brake. What's funny is, it does this when you are going downhill. It doesn't really do it going up hill.

Any ideas on what's going on?

Thanks for your help.