My 1992 400e Mercedes runs and idles very poorly when it's first started.

What is your question?

It runs lean and very rough for the first few minutes. After the warmup, the emission control air compressor stops, and at the same instant, begins idling good and runs great. It sometimes stalls when it's warm, and won't start at all until it cools back down. It's possibly a wiring harness, but I am reluctant to replace it, until I am sure of that diagnosis.