SL Hesitant Accelleration for first 15 minutes, once in a while

[Captain Scott]

Hi gang,

Can anyone take a guess at why every once in a while my 74 450SL runs really rough with poor accelleration and pushes out fuelly smelling smoke while under 2000 RPM? Right as she passes 2000 and above, she smooths out but still has weak and bumpy accelleration. She never thinks of stalling, just a rough and weak gas pedal. After 10-15 minutes, the symptoms gradually go reside and by the time I get home, it is purring as usual. This happens maybe once every other week and does not seem to be outside temperature dependant. I have checked the cap, rotor, plugs and points and variouse wiring, but eveything seems ok. I've made a cursory check for vacuum leaks, but the hoses and connectors seem OK, too. I do not know the history of the injectors/seals, but read somewhere that injector weep might be a suspect. What else might cause this behavior???

I inherited this car 6 months ago and this problem is apparently a new issue and may be worsening. I called the cars old merc mechanik (in her old home area in Socal) and he told me he had given very thorough maintenance to this car and he did not know might be suspect. But then he is 1000 miles away now.

Rather than drop her in the lap of some local mechanic with no diea of where to start looking, I would like to try to offer him some possible angles.

Anyone what to take a shot here??