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M103 tuning in north east

Discussion in 'Tuning, Styling and Performance.' started by guy1969, Aug 6, 2018.

  1. guy1969

    guy1969 Member

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    Joined:
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    Your Mercedes:
    1989 300se
    I am after having my 1989 300se with an m103 engine properly tuned as it is definitely running rich. Have changed the plugs leads distributor cap and rotor, now want to have it tuned correctly, does anybody know an independent garage in the north east of England who has knowledge of this injection system and the engine in general who could do a full tune up?
     
  2. DREAMER NO2

    DREAMER NO2 Senior Member

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    Joined:
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    Location:
    Kidderminster in Worcestershire
    Your Mercedes:
    W124 2.6E M103
    If your on the rich side . Now this is what i would do first. Get the garage to remove the injectors and have them cleaned, and checked at an auto injection shop . From there you might have to replace one or 2 of them, even more you wont know till they are checked out .. At the same time replacing the seals , seats and O rings . . This over rich mixture might be a combination of things .Best to start with these injectors first . You can bet they have never been out the engine from its rebuild to start with .And yopu can go on from there with help from the forum members.. On you economy guage where is the pointer sitting at at tick over ?.
     
  3. onefortheroad

    onefortheroad Senior Member

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    Location:
    uk.
    Your Mercedes:
    E
    ron perry at a19 tune had an impressive set up , not sure if its still open tbh .

    he uses road n roller to get live feedback and a full printout of results . he then goes on to adjust things and reruns the test showing new data and results.

    https://www.ronperry.co.uk/a19-test-tune/
     
  4. OP
    guy1969

    guy1969 Member

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    Your Mercedes:
    1989 300se
    To be honest the economy gauge sits right in the Green the only signs of it running rich really are on tickover there is raw fuel coming out the tailpipe and a strong smell of fuel when you remove the oil filler cap also it's not returning very good miles per gallon. It has a slight miss on tick over and the smell of unburnt fuel from the back end of the car is quite strong
     
  5. DREAMER NO2

    DREAMER NO2 Senior Member

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    Location:
    Kidderminster in Worcestershire
    Your Mercedes:
    W124 2.6E M103
    GUY The economy gauge pointer should sit right over to the left on tick over...in any other place then you have a fault Do you know the location of the fuel pressure regulator ? its under the air filter on top of the engine . From the rear of it runs a small bore tube that goes in to the rocker box cover via the breather hose .. Do you see or smell fuel in the pipe . Fuel leaks out of the pipe in to the rocker box, thats if the diaphram is split inside the f/p regulator . See pic of fpr its next to the metering unit with rubber s shaped hose on the rear of it
     

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  6. OP
    guy1969

    guy1969 Member

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    Your Mercedes:
    1989 300se
    Cheers dreamer I will check that out asap..so the plastic pipe will smell of fuel? Will fuel drip out on tick over
     
  7. DREAMER NO2

    DREAMER NO2 Senior Member

    Messages:
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    Joined:
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    Location:
    Kidderminster in Worcestershire
    Your Mercedes:
    W124 2.6E M103
    Yes in to the rocker box and then in to the sump via oil feed . The little clear tube in the picture top left hand side by the rocker box spigot the vent hose fits to ,thats the tube it will show petrol if the diaphram is split .While the air box is of check on the sides of the fuel distributor and metering unit they have a smal box fixed on the side they also can leak fuel .
     

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