> My 1997 300D has difficulty starting when the tank is half a tank full or
> less. Is there a problem with the fuel pump or pickup? It doesn't matter
> what the temperature is outside for this to happen. It starts just fine when
> the tank has more than half full.
>
> Any help?
A possibility is that the fuel prefilter is partly clogged and
restricting the flow of fuel.
I have the same symptom on my 1977 300D when my prefilter is getting
clogged. The underlying cause is so-called "algae" living in the fuel
and breaking it down into a black sludge. That would likely be the
problem where you must change the filter frequently (i.e.,
significantly more often than the 30,000 miles recommended by MB).
phollings