I have a 1990 560 SEL that's getting too much fuel. I have replaced the fuel distributor, EHV, O2 sensor, pumps, etc. The CIS checks out OK, and after cleaning the engine with a MotorVac it runs OK for a while, then starts to choke on fuel again. Seems to do this right after I fill the tank, mileage goes from 19 mpg to <7 mpg within a few miles before car won't run anymore.