[W126 Coupe] Vacuum Regulator

[DCrawford at tompkinsinc.com]

I recently had the same high idle speed problem.  Turned out to be a fuse
related to a relay.  I never took the time to ask the tech where the relay
was because I was thankful the the bill fore the word was so inexpensive.

This note is more in the spirit of brainstorming, not suggesting a specif
solution.  Good luck.......

Dave Crawford 
84 500 SEC

-----Original Message-----
From:	Chet Hwilka [mailto:chwilka at comcast.net]
Sent:	Sat 12/4/2010 11:40 AM
To:	'Dan Gardner'; 'Mercedes Coupes Mailing Lists'
Cc:	
Subject:	Re: [W126 Coupe] Vacuum Regulator

Dan,

There are several places for air to leak into the system after the throttle
and slide valve which would cause the hi-idle.  But it would require
removing the mixture assembly and intake manifold and replacing all the
rubber pieces associated with air intake.
See fig-8.
http://home.comcast.net/~chwilka/cylinder_head_removal_and_replac.htm

It solved my hi-idle and that was after shot-gunning the idle slide valve
and controller..  waste of $$$..  Although even after all head work, the
idle was still a little high, after correcting the valve timing, it was dead
on..
Of course your guy should have eliminated any electrical problems first
(i.e. broken wires, poor connections, faulty throttle switches, etc)

Chet



-----Original Message-----
From: mbcoupes-bounces at mbcoupes.com [mailto:mbcoupes-bounces at mbcoupes.com]
On Behalf Of Dan Gardner
Sent: Saturday, December 04, 2010 9:40 AM
To: mbcoupes at mbcoupes.com
Subject: Re: [W126 Coupe] Vacuum Regulator

Hi Folks

    As I have been plagued with the high idle problem,which even the German 
factory trained "Guru"could not seem to locate.The idle speed controler has 
been swapped(as well as the valve) so I have been thinking of fitting an 
adjustable vacuum regulator in the line between the valve and manifold,this 
may well be a crazy idea,but I have cut the idle down by 200 rpm by sleeving

the valve with a plastic tube,but because it fluctuates from day to day I 
would be nice If I could fine tune it,any thoughts on the matter would be 
most welcome.

 

                Kind Regards Dan Gardner     1986  560SEC  (Euro 220kw) 

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