I would start a new thread with the latest info and hope for some further input from the members. I would try and read any codes that might be stored. See if you can borrow a code reader or get to an Autozone where they can do it for you. A slim chance your new part was defective. If you got it locally, you might be able to swap for another one.

Good luck,

glenmore
1991 300CE
2000 C280