digging around the recesses of my memory, you should (in order..)

check system pressure
check control pressure
adjust open loop CO
verify duty cycle varies when closed loop

there's more of course, but that's the quick and dirty.
One other thing to check/verify is that with the boot off, clean the air flow sensor housing and plate, top and bottom, using 3 .010 feeler guages, slightly loosen the bolt holding the plate and using the 3 feelers, center the plate and tighten the bolt.

While I haven't worked on too many CIS-E MB's, I've spent the better part of my adult life working on Audi's, VW's, and Porsches.

Bentley does have a good book on Bosch fuel injection systems,but you'll likely have to dig around for one.


erie