1989 Mercedes 300E flat acceleration on first start

For more than a year I have had a flat acceleration from from the first start of the day, no matter what the air temperature might be. Once the engine warmed up just a little bit the car would drive fine for the rest of the day. Finally I found a blog about this problem, and it is so simple, these cars are designed to run as lean as possible and a simple adjustment of the EHA valve fixed the problem.