JNT,
Thanks for the info.

As I said earlier in this thread, I read some threads referencing the coolant temp sensor and the EHA. I adjusted my EHA 1/4 turn CW and that made it idle worse, I then adjusted the EHA 1/4 turn CCW and it is idling fine again. However, it is still running rich since my plugs are fouling, I have black smoke when I gun the engine and I'm leaving black soot on the driveway. I've spent a great amount of time reading the MB shop manual CD today, section 07.3-0121 (testing electrical components of KE injection system). Page 59 references the 4 pin connector that contains the temp sensor input. Page 60 references the volt and resistance values for a properly working temp sensor and page 64 references test setup of 4 pin sensor that seems to contradict information on page 59 since there is a vacant pin referenced on page 59 which would make a measurment setup like that on page 64 worthless. So I'm back to the original question.

Does anyone know definitively how to test the coolant temp sensor?

Thanks,

Bob