That is a common problem! So much so that MB has modified the 2 rubber hoses that connect the idle control valve to the intake.
If you order these hoses & install them properly the stalling should go away.
MB part numbers 116-094-12-91, 116-094-13-91 & 116-997-16-52. Make sure that the small plastic tube is OPEN at both ends.
All of the parts should cost less than $15. TOTAL!
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)