My 1981 244GL ( B23E ) fitted with K-Jetronic injection won't idle above 650rpm when cold.
Does start easily when cold, but refuses to idle above 650 until the engine is warm when it sits at a steady 950rpm ( as it should )

I've looked at the auxilliary air valve, and the condition is as follows:-
When cold, the sliding valve is 90% shut. Only reason I'm not stating it fully shut is the sliding valve shape is not totally circular, rather like a cutout shape at 4 oclock.

Am I correct in assuming the valve should be open when the engine is cold ?

When engine is warmed up, the valve is in the same position, have noticed if I pinch either of the airlines the idle decreases. Ohm readings are 47.6 ohms at the valve terminals when hot or cold, 25.7 ohms at the wiring connection ( one blue wire, one black wire. 0.0 volts at with engine off or engine on.

Noticed there is an adjusting screw and locknut to the left of the valve body on the upper side. It is marked with yellow paint, suggesting it was set from the factory, can this be adjusted or fiddled with to ascertain if it can be made to work ? If i do fiddle with this valve can anyone advise the amount of opening required at say 0 degrees C ( 32 degrees Fahrneheit ) ???

From what ( little ) I understand, there is a bimetal strip inside this unit which should hold the valve open when cold and gradually close the valve as engine operating temperature is reached.
So.....if i'm looking in a junkyard, it could be reasonable to assume that one of these valves if the disc is open then it's probably operating okay ???

Conducted a small experiment - using a piece of wire to hold the valve disc open and voila, the engine revs soared to approx. 2500rpm.
The unit is now in the fridge, ready for the next experiment.
Yes, the disc moved a little and opened. With a heat gun on low I heated the unit a little until approx. eng. temp. ( I think ) and the disc closes.
Now I need to know approx. how far open the critter is when at a measureable temperature.
Figuring this is really a matter of adjustment to have a win - am i on the right track ??


Thanks, looking forward to knowing a little more and getting the cold idle back up to where it should be.
cheers
richo
'81 244GL B23E K-jetronic equipped, driven by caring if somewhat challenged owner.