How to increase "idle" speed on a W124

[Jukie]

My idle speed (E220) is a little low. About 500RPM in PARK, dropping to under 500RPM whilst stationary with foot on brake and DRIVE or REVERSE engaged. This has led to the engine cutting out a few times this week.

How do I up the revs just enough? A detailed description with pictures would help!!

TIA, David.

 

[DieInterim]

Hello,

Engine speed is controlled by the ecu (COMPUTER) and a electric valve. Clean your ICV (IDLE CONTROL VALVE) and recheck your idle after the engine reaches operating temp. There is also the possibility that you have a air leak somewhere, but clean the valve before anything else.

Cheers,
Blake

 

[Jukie]

Hello,

Engine speed is controlled by the ecu (COMPUTER) and a electric valve. Clean your ICV (IDLE CONTROL VALVE) and recheck your idle after the engine reaches operating temp. There is also the possibility that you have a air leak somewhere, but clean the valve before anything else.

Cheers,
Blake

Blake,

Thanks for this. I now know about the ecu controlling the engine speed! Are you able to tell me where the ICV is and how to remove, clean and replace it? I have no experience working on this engine nor access to manuals, etc.

TIA, David.

 

[television]

I was hoping to get hold of the 1990-1995 Alldata book and photocopy the MB section, I have the pre 1990 back to 87. It would be very useful in cases like this to be able to give the correct testing info

 

[Ian B Walker]

If you adjust the throttle cable (knurled adjuster at the engine end) you can increase the rpm.