500SL Low RPM Hesitation

[Kquillan]

Hi Everyone - I am new here as I just purchased a 1992 500SL and have some issues I need to address. Most notable are a set of symptoms I think are related (1) "rough" idle" between ~550-650 rpm when, mostly when cold and only in park/neutral, (2) hesitation and lack of power below 1800ish rmp for the first 2-5 minuts of driving, (3) must pump throttle to start, mostly when cold, and (4) some poorly-times shifts for first 2-5 minuts of driving.

The hesitation "clears up" mostly if I get on the throttle and need to get moving (when pulling into an intersection). But it will do it again when coming from a stop at the next intersection. After driving for a few minutes, the car runs perfectly! It's a blast.

At first, it seemed the issues were temperature-related, but I had the car warm and stopped driving for 30 minutes yesterday - same hesitation for a couple of minutes after startup. I don't smell gas, and it's hard to tell if it's just running rich or not getting a good spark. Has the CIS system (early 92').

I appreciate any thoughts on what this may be!