Erik,
if I understood you right, everything is ok, when the engine is warm, but she dies when idleing cold. You have to play with the pedal, to keep her alive, right?
You know, there is a loooong list of values to check, if you start from the very beginning, it's all listed in the workshop manuals, available on CD in German or English.
But it sounds to me, that your engine runs too lean during cold start and therefor dies.
Check the engine temp resistor, black plug with four pins underneath.
Values are as follows:
18 kilo Ohms at -20 °C
6 kilo Ohms at 0 °C
2,5 kilo Ohms at 20 °C
you have to messure these at position 2 against 7 and 5 against 11 o'clock.
If the values are out of range, try another resistor, they are all the same in these late KE-engines, if it looks like yours, you can use it.
If the values are within given data, check the wires from the resistor to the KE-ECU for continuity.
Two wires go the KE ECU pin no. 7 (ground) and no. 21, two other go to the EZL ECU, one is grounded as well. Maybe you have a good resistor but a broken wire...
If this won't work, you should go through the complete procedure as documented in the WIS.
Do you do your own work or do you have to pay someone, for doing it?
good luck,
bis denn,
Christian
1989 300TE
1984 2.3-16