Engine (hot) stalls while idling

Okay Claudio,

so you do not have sudden change but warm engine runs badly. You can only keep it running at medium rpm.

A cold engine runs normally better than a bad running warm engine. It has more fule and higher rpm due to AAV being open. When it gets warm these effects cease and now it should run all by itself. If that mixture does not fit then you have the effect as described.

You should start with ignition timing. Check it at idle, 1500 and 3000 rpm and check vacuum retard according to MB workshop manual. Fuel pressure was checked by you I know. Then please measure manifold vacuum by inserting a T-piece in hose to MAP sensor for a vacuum gauge.

Did you already adjust idle exhaust gas? Where is CO and HC ?

Hi everybody, 
Yesterday I installed a new ignition coil(right Bosch code). I started the engine and waited for the engine temperature to reach 80 degrees..the engine did not turn off by itself. After that I went on a small country road for a little ride...feeling that the rpm were low in idle mode..I turned two turns of the air passage screw...the rpm went up to the right point.
Basically I think I have solved the problem..although I want to bring everything back to the original so soon together with a mechanic I will mount the original injectors and rebuild the fuel line as per the Mercedes diagram.
I still have to study my old Bosch manuals (they are in German so I have to translate them all) to be able to perform all those maintenance tasks that the great Volker listed on this site.
 
Thank you all.
Claudio

Hello Claudio,
then you can on 10.09. have a nice birthday trip with your Mercedes
BR Hans-Jürgen