Author Topic: Another 6.9 that wont raise (diagnostic tips)  (Read 794 times)

secondslc

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Re: Another 6.9 that wont raise (diagnostic tips)
« Reply #30 on: 19 May 2020, 02:45 PM »
I need to get a bulb in that spot as its burnt out, but I should probably let the light tell me if im reaching pressure...
1979 6.9
1983 urQuattro
1991 200 20V Avant
1993 Corrado SLC
1996 SL600
2009 Super V8

secondslc

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Re: Another 6.9 that wont raise (diagnostic tips)
« Reply #31 on: 31 May 2020, 08:56 PM »
Put a used pump in. The old one was wet on the back... assuming it was leaking into the block ugh.

-Primed it as per suggestions in the forum
-Hooked it all up
-Started it
-The pressure selector finally started clicking.
-The rear end lifted up as if magic
-The front end lifted up as if magic

After 20 years, it drove around the block on its own.  :D

Next up I get to tune the engine as it's low on power.
But first:
-Change the plugs
-Change the oil
-replace the hydraulic oil filter
-Oh, and celebrate :-D
1979 6.9
1983 urQuattro
1991 200 20V Avant
1993 Corrado SLC
1996 SL600
2009 Super V8

daantjie

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Re: Another 6.9 that wont raise (diagnostic tips)
« Reply #32 on: 31 May 2020, 08:59 PM »
Nice work!
Daniel
1977 450 SEL 6.9 - Astralsilber

rumb

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Re: Another 6.9 that wont raise (diagnostic tips)
« Reply #33 on: 01 June 2020, 07:52 AM »
Good news.

Check your timing, that should help with power.
'68 250S, '77 6.9 euro, '91 300SE, '98 SL500 '14 CLS550

daantjie

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Re: Another 6.9 that wont raise (diagnostic tips)
« Reply #34 on: 01 June 2020, 07:55 AM »
Changing out transmission fluid and filter should be high on the list too.
Daniel
1977 450 SEL 6.9 - Astralsilber

secondslc

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Re: Another 6.9 that wont raise (diagnostic tips)
« Reply #35 on: 01 June 2020, 03:23 PM »
Timing... any leads to a procedure?

Trans was empty as the cooler lines were shot. Replaced all the lines and put new fluid in. It shifts ok but itll get flushed once its road legal
1979 6.9
1983 urQuattro
1991 200 20V Avant
1993 Corrado SLC
1996 SL600
2009 Super V8

raueda1

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Re: Another 6.9 that wont raise (diagnostic tips)
« Reply #36 on: 01 June 2020, 03:45 PM »
Timing... any leads to a procedure?

Trans was empty as the cooler lines were shot. Replaced all the lines and put new fluid in. It shifts ok but itll get flushed once its road legal
MB manuals are on this site.  Here's the link:  https://img.w116.org/tech/Manual_100-985_Combustion_02_83.pdf
Drill down to the section on timing.  Specs are there.  Before doing so, however, make sure the elements of the distributor can move freely and aren't gummed up (quite likely if the car has been sitting for years).  And if so, you'll never get the timing right. Good luck!
-Dave
Now:  '76 6.9 Euro
Before that:  1966 230S, 1964 220SE coupe, 1977 Carrera 3.0

secondslc

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Re: Another 6.9 that wont raise (diagnostic tips)
« Reply #37 on: 01 June 2020, 04:24 PM »
Thank you for this! I have a hard time finding the tech articles for the 6.9 specifically.

The distributor moves, it was loose when I got the car  :o

1979 6.9
1983 urQuattro
1991 200 20V Avant
1993 Corrado SLC
1996 SL600
2009 Super V8

raueda1

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Re: Another 6.9 that wont raise (diagnostic tips)
« Reply #38 on: 02 June 2020, 08:05 AM »
Thank you for this! I have a hard time finding the tech articles for the 6.9 specifically.

The distributor moves, it was loose when I got the car  :o
My grandmotherly and forgetful neighbor repeatedly calls over to me as she trims her roses, "David, you're always working on that car!"  And my reply is always the same.  "Glenda, this isn't a car.  It's a hobby and way of life!"  A week later this will be repeated verbatim.

Anyway, the tech page https://www.w116.org/tech/.  The 100.985 manuals are the ones you want.  The quality is not great and photos are near useless, but they're there. A lifesaver.  Thanks to whoever put them up in the first place!
-Dave
Now:  '76 6.9 Euro
Before that:  1966 230S, 1964 220SE coupe, 1977 Carrera 3.0

revilla

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Re: Another 6.9 that wont raise (diagnostic tips)
« Reply #39 on: 02 June 2020, 08:28 AM »
The distributor moves, it was loose when I got the car  :o

Hi secondslc.  I think Dave was referring to the guts (elements, weights, sliders, springs, etc) inside the bottom of the distributor housing.  If they are not clean free of grime they have difficulty responding to the centrifugal forces to advance the timing which will have an impact on power.

He documented the procedure in a post here with details and pictures, etc.  When I did mine following his guideline the improvement was quite noticeable!     

Robert
W116 1977 280SEL & 1979 280SE

secondslc

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Re: Another 6.9 that wont raise (diagnostic tips)
« Reply #40 on: 02 June 2020, 06:51 PM »
ohhh, i am a little intimidated taking that apart, but I suppose it will make sense when i get into it. I’ll report back once I get going.
1979 6.9
1983 urQuattro
1991 200 20V Avant
1993 Corrado SLC
1996 SL600
2009 Super V8