7Cars Forum

What should the RPM number be when my vehicle is warmed up and in park after driving?

Approximately 650 revolutions per minute, I guess.

When I engage the park mode, the RPMs surge to 1000.

In light of this, I will examine our BW W126 archives for high idle or quick idle.

There is an abundance of information and guidance available.

Vacuum leaks, a contaminated idle air control valve, and a potential failure of the Over Voltage Protection Relay or its fuse.

Best of luck.

My previous issue was caused by a faulty distributor cap, resulting in coil wire arcing and the idle system correcting for the misfire. It is rather sensitive.

The RPM at 1000 was adversely affected by poor solder connections inside the Ignition Control Unit. I have seen Mercedes' official comment about this matter. Rewetting solder to enhance milky solder joints has some risks, since inadequate soldering skills may lead to unintended cross connections, which may be difficult to rectify.
What happens to the idle when the Ignition Control Unit is disconnected? If it increases more, it may be functioning partly. Is there any information on the consequences of disconnection?

Other difficulties may also be present; the time might be inappropriate. I like to maintain mine at around 12 to 14 degrees Celsius. I own a 380 SEL that operates properly on ordinary gasoline.

Ignition control or idle control unit?

1000 RPM in park is elevated; but, what is your RPM in drive at idle?