1995 E420 Hot Start Problem

[lowellchu9]

Hello Everyone and Happy Labor Day Weekend,

I have a 1995 E420 with 150K. I have it serviced professionally, and everything is up to date.

However, yesterday, the car experienced a very unusual engine start, and I would like to see if others have had the same, unusual experience.

Here is the sequence of events:
1) I energize the starter with the ignition key.
2) The starter turns over the engine, and it starts to run at <500 RPM.
3) After about 3 seconds, the engine speed suddenly climbs to >1500 RPM for another 2 to 3 seconds. Nothing is near the throttle....
4) Engine returns to normal idle speed.
5) Engine (and drivetrain) behaves normal thereafter.

The behavior is now continuous.

Please advise.

Lowell C.