The answer is simple - one word, really : SATAN. I think German cars suffer
from fuel economy gremlins like British cars suffer from electrical
problems. Don't worry. It will go away. I'll get 19 MPG one week then about
9 the next, then back up to 19 . . . I have learned to just ignore it -
only thing that worries me about it running excessively rich is from engine
wear due to rich startup which causes unburned gasoline to wash oil off
cylinder walls. Nice thing about old carburated engines is with a manual
choke you could open it up and keep the engine revved about 1700 rpm by
foot until it was warmed up . . . . .