Thanks for the input,
The 02 sensor is new. I have changed everthing except the ecu and I have the same problem of running rich. as I had with all of the original equipment. Nothing I have done so far has had any effect on the problem.
I could probably return all the original parts and still have an engine that will not run with the eha plugged in.
Here's what I don't understand, if the engine is tuned without the eha plugged in, why, when the eha is plugged back in does the system not just fine tune the motor, instead of stalling it?
Is the ecu on this vehicle a unit with a history of design problems or has it been fairly reliable?
I am not aware of a airflow sensor on this vehicle. The availability of shop manuals etc for this car seem hard to get. I subscribe to Mitchel on Line for this car, and even they don't have a vacuum diagram for the 260E.

Once again thanks for your input
Michael