Hello Potomac Pat,

I am glad there is someone in the world who also thinks that a bad temp sensor input is causing problems to the car.
My car 1989 230E has 2.3 liter 8v engine. It idles at 800 rpm when the ingine is hot or cold. I think that the car should idle at higher speeds when cold. Disconnecting the temp sensor should change the engine's speed. My car does nothing when I disconnect the 4 pin temp sensor. I have posted it's picture. The temp sensor is part #1 in the following link.
1 engine, 3 temp sensors?
If you can read the schematic you can look at the KE Jetronic system's detailed schematic below. It will take you 20 seconds to download this with a modem. Don't ask me if I can read the schematic for you because I don't understand !@#$ in this.

http://www.autolib.diakom.ru:8001/CARS2/main/Mercedes-Benz/shematic/controller/KE-Jetronic/mke.pdf

Hurshi

__________________
1989 230E, 8v, 166.000 km, updated to 94/95 trunk & hood
2002 Daewoo Nexia 50.000 km
Sold:
1987 VW Jetta GLE 16V, Recaro seats
1982 Volvo 240 DL (lovely car!)
and few more american cars.