You might try searching that type of problem.

The most common problems that cause that problem are....the idle valve itself, the idle contact switch, the de-cel shut-off switch, the air flow position sensor, & the hall-effect speed sensor.

__________________
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)
Retired Moderator