[W126 Coupe] HELP! Car Salling!!!!!

[David Fatovic]

It sits towards the middle, closer to the left as
looking at it.  

I took my lunch break today and pulled the Idle
Control Valve and cleaned the shit out of it.  Almost
litteraly.  I also cleaned under the throttle plate. 
Now on my way back to the office the car did not stall
on me once, even when warm.  However, idle did get
close to it.  The idle did drop below 500rpm a couple
times at a light.  It was also rough.

So now the question is.  I assume I have a vacuum leak
somewhere that is messing with the idle a bit.  It is
also making it rough.  What is the easiest way to find
a vacuum leak?  I don't have any vacuum test tools. 
Where are the usual leaks found?  

David


--- "Shayegan, Richard" <rishayegan at davidson.edu>
wrote:

> With the car stopped, engine running, in D, where is
> your economy gauge? Anything other than pegged at
> the best fuel mileage side (i.e. the non-red side,
> IIRC the left side) means a vacuum leak.
> Richard
> 
> ________________________________
> 
> From: mbcoupes-bounces at mbcoupes.com on behalf of
> David Fatovic
> Sent: Tue 6/6/2006 1:36 PM
> To: Mercedes Coupes Mailing Lists
> Subject: Re: [W126 Coupe] HELP! Car Salling!!!!!
> 
> 
> 
> Would a vacuum issue also cause some sluggishness
> going from a standstill to the first part of
> accelleration?
> 
> David
> 
> --- Dick Spellman <spell.yy at verizon.net> wrote:
> 
> > Hi David;
> >
> > Glad to hear you found some improvement on the
> fuel
> > filter change.  Any
> > way you can test fuel pressures on the system to
> > rule out the pump,
> > regulator, etc?
> >
> > As for the unstable idle...You may well have
> several
> > gremlins occurring
> > at once.  It should be relatively easy to test the
> > throttle position
> > sensor (TPS) using a VOHM meter.  If the idle
> > position is not showing
> > 'closed' while the engine is at idle, then you
> could
> > have a carbon
> > build-up on the throttle body that needs to be
> > cleaned or the TPS itself
> > may have failed.
> >
> > If the TPS shows open when it should show closed,
> > just jumper the two
> > pins on the harness to fake the 'at idle' position
> > to see if this
> > improves the stability of the rpms at idle.  The
> TPS
> > is 3 pins total. A
> > center pin which is 'common' and a pin to either
> > side that reflect 'wide
> > open throttle' (WOT) or At Idle.  Be sure you know
> > which is which as you
> > proceed with the test.  Then at least you will
> know
> > what to repair
> > before going further.  There are a number of other
> > things that could
> > cause that erratic idle as well but, this is one
> > that's easy to check
> > and rule in or out in making the repairs.
> >
> > Dick
> >
> > David Fatovic wrote:
> >
> > >do you remember where you found the computer and
> > >wiring harness. I will want to check that out as
> > well
> > >
> > >I changed the fuel filter tonight. it did make
> some
> > >difference. here is what I found while driving it
> > >tonight. it goes well while driving, but when you
> > stop
> > >it doesnt hold idle very well or at all. that is
> > when
> > >it will stall. it tries to idle around 480-500
> rpm.
> > I
> > >believe that is too low to keep vacuum pressure.
> > what
> > >could cause this? I did replace the over voltage
> > >protection relay.
> > >
> > >any ideas now? what should I look at to adjust
> the
> > >idle?
> > >
> > >thanks,
> > >
> > >David
> > >--- mbcoupes-bounces at mbcoupes.com
> > ><igatenby at optushome.com.au> wrote:
> > > 
> > >
> > >>-----Original Message-----
> > >>From: mbcoupes-bounces at mbcoupes.com
> > >>   
> > >>
> > >[mailto:mbcoupes-bounces at mbcoupes.com] I
> > > 
> > >
> > >>had the same problem - swapped lots of parts
> > between
> > >>   
> > >>
> > >my 500SEC (which had
> > > 
> > >
> > >>the problem) and my wife's 500SE.  In the end
> > (after
> > >>   
> > >>
> > >months of chasing the
> > > 
> > >
> > >>problem) it turned out to be that small wiring
> > >>   
> > >>
> > >harness that attaches to the
> > > 
> > >
> > >>ignition computer - it had a wire that was
> broken
> > >>   
> > >>
> > >inside the insulation. 
> > > 
> > >
> > >>$15 at the wreckers' - problem solved.
> > >>
> > >>Ian
> > >>
> > >>The MB Coupes Website!
> > >>W126 SEC Mailing List
> > >>Postings remain property of MB Coupes, L.L.C.
> > >>   
> > >>
> > >
> > >The MB Coupes Website!
> > >W126 SEC Mailing List
> > >Postings remain property of MB Coupes, L.L.C.
> > >
> > > 
> > >
> > The MB Coupes Website!
> > W126 SEC Mailing List
> > Postings remain property of MB Coupes, L.L.C.
> >
> 
> The MB Coupes Website!
> W126 SEC Mailing List
> Postings remain property of MB Coupes, L.L.C.
> 
> 
> > The MB Coupes Website!
> W126 SEC Mailing List
> Postings remain property of MB Coupes, L.L.C.