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

[Dick Spellman]

Hi Dave:

So you may have some recourse with the mechanic who just replaced a 
possibly good ignition control unit but, in the meantime you need to 
either diagnose the problem yourself or go back to the mechanic and tell 
him to fix the problem.

If you choose to look into this problem on your own, I'd start by using 
a heavy gauge jumper wire across the correct two fuel pump relay 
terminals (relay removed temporarily) and drive the car to see if the 
symptoms are gone or still present.  Once you've run the road test with 
jumper, replace the original fuel pump relay.   Do not leave the jumper 
in place when the car is not in use!  An then let the list know what you 
found.   By the way, a new fuel pump relay for the 85 500SEL is about $80.

Regards,

Dick

David Fatovic wrote:

>The problem is he replaced the ignition control and
>the problem is still there.  Before when the ignition
>control went out. You were completely unable to start
>the car no matter the temp.
>
>David
>
>--- "David G. Cole" <dc at dc-mc.com> wrote:
>
>  
>
>>Dave,
>>
>>Not necessarily, my '85 ignition control unit went
>>on the fritz and, in
>>the beginning, would only fail very intermittantly
>>and only after it was
>>running for a good bit and got hot. As some time
>>went by the frequency of
>>failing increased as the amount of time it took,
>>from first startup to
>>stalling, decreased. Finally got to the point (and
>>in a very short amount
>>of time) of being able to run only 10 to 15 minutes
>>before it gave out.
>>
>>But all things considered, the fuel pump relay has a
>>known history of this
>>same type of sympton while the ignition parts are
>>usually very solid.
>>Focus on the fuel relay first.
>>
>>David Cole
>>
>>
>>    
>>
>>>I need some help with my dad's 85 500SEL.  The car
>>>seems to stall when it gets warm.  The strange
>>>      
>>>
>>thing
>>    
>>
>>>is, it doesn't seem to be only when the car is at
>>>idle.  But driving down the highway the car will
>>>      
>>>
>>stall
>>    
>>
>>>out.  My dad took it to one mechanic who changed
>>>      
>>>
>>some
>>    
>>
>>>vacuum tubes and then charged him to change the
>>>ignition control unit (which I have replaced
>>>      
>>>
>>before).
>>    
>>
>>>Now if it was the ignition control unit the car
>>>      
>>>
>>would
>>    
>>
>>>not start at all because it wouldn't be telling
>>>      
>>>
>>the
>>    
>>
>>>coil to release its charge.  But after the car
>>>      
>>>
>>stalls
>>    
>>
>>>it starts up again.
>>>
>>>So I am thinking that the mechanic just took us
>>>      
>>>
>>for a
>>    
>>
>>>ride, but I don't know what else it could be.  I
>>>      
>>>
>>know
>>    
>>
>>>people have had this issue or something similar
>>>before.
>>>
>>>Any ideas on what we should look at?
>>>
>>>Thanks,
>>>
>>>David
>>>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.
>
>  
>