Engine only able to start when cooled down could point to ezl failure. Do you have a spare ezl to try out? Perhaps borrow a known good unit some someone
I just wanted to rule out a fuel issue being the explanation for the hesitation. As for not using any fuel additives, I tend to go by the recommendations of the MB engineers as well as my engineer father who had more than 40 years of engineering experience.w201fan, The filter was installed less that 5000km (3000miles) ago. I only use premium gas (91octane). I live in a rural where all of my trips involve highway driving.
I have had good experience with certain additives in my vehicles, boats and aircraft.