Have you checked that?
Cold start enrichment vavle or whatever it is that helps cold start?
Fuel injector nozzles?
maybe a bad plug that smooths out when it gets warm?
My bro's car sounded like it was choking the other day, changed plugs and its perfect now.
Its a range rover though.
'92 300CE - Sold
2004 C240 - C7 Wheels
2015 ML350 - P1, Pano, Ash poplar wood, Sport Dinamica interior, Running Boards Keyless go.