IDLE ADJUSTMENT 1987 300 t diesel
 

How can you adjust the idle on a 1987 300 t diesel,its low,on the old 5 cylinders was easy,on this one I dont see any accesible idle adjustment

On the false firewall near the fusebox, there's a black knob labelled "ELR" with several numbers on it. A higher number corresponds to higher idle speed. Pull the knob out to turn it. This is actually a LOT easier than the adjustment on the old 5-cyl turbodiesels. ;)

The main way is as Speedy described. There is a set screw and I think it's parallel to the crankshaft and extends beyond the IP case in the area of the idle control actuator at the back of the IP. Unplug the idle control actuator and set base idle at 620 +/- 40 rpm. Plug the idle control actuator then set the ELR for 680 +/- 20 rpm. Of course the most difficult thing is getting your hands on a Diesel tach. You can trust the gauge cluster tach or tap into the fly wheel rpm sensor at the Klima relay connector pin 2. I don't know how to interpret the signal. If you touch the base setting with the ELR connected the ELR will do what it can to counteract your adjustments.

Sixto
95 S420
87 300SDL