Well I ain't to sure about that hypothesis. I had/have a similar problem, however I have a slighly rough idle, and 2. sometimes it takes one or two cranks to start , and I have to pump some gas. I knew it was fuel related, and I was leaning towards injectors, and my hypothesis was similar to yours. However I took it to a good Merc shop and it turned out to be my fuel distributor, which is a bit faulty. Who diagnosed your car??

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