Your specific car is pretty rare and you won't find too many people with experience on the EVO I or EVOII models here. The original 190E 2.3-16 made it to the States though, and there are a number of us who frequent the site.
Try a search on the 190E 2.3-16 idle problems, or stalling. It is a fairly commonly reported problem and not all solutions are horribly complex, but some are. In some cases there are some limit switches that get munged up and need to be renewed or cleaned, while others involve removing the idle control valve assembly and either soaking it in a solvent and blowing it out with compressed air, or replacing it. Still others have much more complex issues and get into recalibrating the fuel delivery/air flow sensing equipment. Some or all of it will apply to the 2.5-16 engine, but you will have to sort that out. Good luck, Jim
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)