All 4 Mercedes I have had (116-450sel; 116 6.9; 108 6.3 and 126 420sel) have experienced hot start problems; best and only solution has been changing the rear fuel accumulator located by the gas tank same area as fuel pump(s); cheap part @ $35-40.00. learnt the hard way with my first problem car that after spending many $$$$ in fuel inkection parts, fuel pumps, fuel distributor it turned out to be the fuel accumulator. Try it before anything else and will save many $$$$ and headaches no matter what some mechanics tell you.
KJ