The 1980 on 240D had no cable control. It only had vacuum control.
The adjustment that matters here is an 8 or 10mm nut that holds the ball to the injection pump arm. From this ball is a link to the plastic proportioning valve at the rear of the injection pump.
With the motor off pull the linkage to full throttle. There is a full throttle stop built into the plastic proportioning valve. The lever that is moved by the link from the pump lever, should about hit that small roll pin that is the end stop, The 8 or 10mm nut allows the ball stud to be moved in a slot in the pump lever.
Do the full throttle thing and get a good idea how close the proportioning valve lever comes to that roll pin. Now adjust the ball in its slot "up" in small increments. I would start with about a .020" movement (about two thirds of a spark plug gap). When done you will have the WOT position of that proportioning valve lever closer to the end stop (to make the shifts later).
Bosch Master, ASE Master, L1
33 years MB technician