Newbie here. Have a 1989 300E with 123,000. The car runs great and idles smoothly yet occassionally it wants to stumble or fall on its face when I accelerate from idle. I noticed if I do the "two foot" trick and barely increase the idle to approx. 750-800rpm (per the tach) it will accelerate smoothly.

Without going down the road of replacing everything known to be a potential problem, could it be that the idle is just a tad low? It idles at approx 600-650rpm while at a stop with the trans in park. If it is low how can it be adjusted?

Thanks for the help!