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

[David Fatovic]

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.
>