After fulltime revision the Mercedes diesel would not run smoothly while stationary.
Investigation led to a suspect valve in the Dracor fuel filter. It seemed to let some air into the fuelline towards the engine.
After replacing the O rings the engine started to run ok after 30 seconds.
Our not so clean Racor:
The inter cooler of the main engine was mostly clogged up with dirt. It was cleaned and a fine filter was installed to prevent dirt from entering the intercooler again. We can now easily spot dirt in the filter via the looking glass.