Fuel Mixture

[Hoolie]

I have a 1973 350se and want to check/reset the fuel mixture. Any suggestions on how I can do this and where the adjustments can be made. Any suggestions on how to improve mpg....
:bannana:

 

[Madferrit]

A start would be to post this in the Engine section.

 

[Steve_Perry]

Moving...

S.

 

[guydewdney]

thats got to be D jetronic in '73 hasnt it?

theres not a lot of easy adjustment - but the idle adjustment is on the ecu - its a small wheel. The ecu is usually just behind the panel by the drivers or passengers legs.

Why do you think it needs adjustment?

Try a google search for d-jetronic - the same system is used on a LOT of cars (porche, saab, volvo, merc etc etc)

 

[guydewdney]

oh - hang on - thats the M116 - thats CIS - or mechanical fuel injection - (try a google on CIS injection)

theres a lot of adjustment on the plate and the fuel pressure screws - but if you dont know what you are doing (and, no offence, but you obviously dont, otherwise you wouldnt be asking here! ) you can royally screw it up...

Guy

 

[grober]

Haynes manual 63030 ( 698)

Haynes American division publish a manual for the merc 350 no 63030 (698). this details how to set the mixture. not sure which fuel system you have. some have a mixture control screw/wheel on the electronic control unit located at the side of the footwell??? other - CIS adjustment is on the top of the mixture control / distribution unit maybe under a plastic plug. It needs a hex key to adjust it ? as guy says not really a diy job to undertake without some experience and a good co meter.

 

[Hoolie]

Thanks for the info

 

[Dieselman]

If it has the mechanical setup then the mixture adjustment is a small allen screw down through the top of the main body. The screw alters the position of the fuel metering needle in relation to the air flap.

Check such things as the throttle body and all vacuum lines before adjustment.