Could someone please tell me which direction to turm the MPU adjustment screw to lean the fuel mixture on my 1972 350sl.
The adjustment screw faces away from you. I read somewhere that turning the screw clockwise leans the mixture.
Does turning the screw clockwise screw the adjustment screw into the unit or back it out of the MPU?



Thanks,


Knarf

__________________
72 350SL #69
73 450SL Parts Car?
78 450sl Parts Car
79 450SLC - Sold
1985 280sl
87 190E 2.6 - Donated
90 300E-Junked
97 E420

Always hard to remember the various places such adjustments matter. When you are doing it properly with an exhaust gas analyzer it is apparent. I don't remember.

The knob adjusts in distinct increments (clicks) move it 4-5 one direction...pause... move it back and go the other direction. Go the direction that makes the engine run faster. If it doesn't matter then return to the beginning and leave it alone. There is only about 2-3% CO change from one end to the other if I recall and none of it matters to anything but idle as the circuit is removed when the throttle switch is opened.

__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician

Steve,

Thanks for the reply.


Knarf

__________________
72 350SL #69
73 450SL Parts Car?
78 450sl Parts Car
79 450SLC - Sold
1985 280sl
87 190E 2.6 - Donated
90 300E-Junked
97 E420