Engine (hot) stalls while idling

Hello everybody, here I am again.

After finally finding and installing a correct Bosch gasoline pressure regulator, I tested my W116 280SE D-Jetronic and unfortunately the problem remains: it does not hold idle when the engine is hot. When it comes on when cold, the engine runs just fine and doesn't stall at all.
Yesterday I drove 4km to get to the gas station..everything seemed ok. Then when I left again, I immediately noticed that the engine would stall at idle speed...and the ride home was unpleasant. Based on your experience...what do you recommend I check? Could a temperature sensor or the AAV be to blame? The fuel pressure is correct..2.0bar. Thank you all. I repeat...as soon as it is started and for quite some time, the engine runs idle fine..at the correct RPMs...the problem arises when the engine warms up.

Thanks and best regards
Claudio
P.S. if you prefer to answer in German that's fine too

Hello Claudio,
does the fuel pressure remain at 2 - 2.1 bar when the motor is warm?
br Hans-Juergen

Hi Claudio,

that is a hard one. An effect that comes only after some time of hot engine sounds like an electrical problem. Mechanical issues would happen earlier. It is most likely not ignition as your car continues ti run. But it would be good to know whether ignition timing fits.

It can be a failing fuel pump or dirt in tank. Hans-Jürgens tip to check fuel pressure while driving is goof. Mount your pressure gauge on windshield.

Or it is D-Jetronic itself. Start with verifying pin 19 (Multimeter to +12V). Must be ground when fuel pump shall run. And then trigger contacts and last signals to injectors.

I would like to point out that if I turn the key just after the engine has stopped warm...the engine starts right away and stays running if I don't go below a certain RPM.
Unfortunately, on my dashboard there is a clock instead of a tachometer and I don't know exactly what RPM number it goes off under.

Hi Claudio,

have you ever measured idle exhaust gas? That could be totally wrong.

And maybe I misunderstood. Engine runs cold and warm well. Suddenly you have a switching point where it stalls if you do not increase rpm. Is that your phenomenon?

Hi Volker, 

let me explain the situation. When I start the engine (cold) it starts right away and it sounds fabulous and runs great. When I do a few miles the problem starts to present itself, and that is under a certain number of revs..the engine simply shuts down. If I turn the key the engine starts right away..but to keep it running I still have to keep the throttle open. In my opinion it is something related to the temperature of the coolant..because otherwise you can't explain that when cold the engine runs great and hot it doesn't. I know your experience is very important...I take advice....

Regards
Claudio