replaced w124 ecu brain; now what?
 

Hi. Well, this weekend I celebrated father's day by replacing the ecu on my 87 300e with one I got for a reasonable price on ebay. And afterward, instead of the fixed 90% reading I had gotten previously, I actually got a fluctuating duty cycle reading, in the 20% range, which I will try to reset to about 50% (I had also replaced the oxygen sensor & OVP over the last few weeks, but that didn't change anything.). My question is this: At lunch today I was browsing through the Mercedes Bible, & it said that (a) the car should sit for 90 seconds key on engine off to allow the ecu to set up and (b) certain codes had to be set. I never did either one of those. Is there anything I need to do for the "new" ecu to achieve proper operation?
I also want to thank everyone on this board for their support, learning and encouragement which enabled me to attempt all the work I have learned to do on my vehicles.

On that car it is just plug and play.