Provide more description of the problem.

From a standing start?
All the time? When warmed up? When Cold? When raining etc

How did the problem develop?

Does it stutter?

Have you checked fuel pressure? Mixture?

Does it idle properly?

And so on.

__________________
'90 300SE 298k
-300K and it gets put into retirement.
'80 300D 255k Purchased new by family in 1980.

Had a:
1973 220 (gas)
1980 300SD
1992 400E