Hi. I am new to the forum. My 85 500 SEL idles very high. Here is what happens. The engine turns over after a couple of seconds of revolutions. When you shift into drive the first time it is relatively smooth, but after the engine warms up the choke does not seem to kick in. This causes a violent clunk and lurch when you shift from drive to park or reverse.

Can anyone help me?

Thanks

Idle speed is computer controlled. There is a protection device for thr idle computer called over voltage relay...possibly a blown fuse in that relay.

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

Thanks so much for that information. Is this a relay located in the firewall box? I recently replaced the fuel relay. Thanks again

On USA models the over-voltage relay in in the fuse box.

The idle speed computer is bolted to the firewall under hood.

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator