eradic idle on 190e
 

have fixed most issues but one still plauges me. when setting the idle on my 1984 190e 2.3 it seems fine for about 3 or 4 minutes and then goes really low to around 500 rpm. I have tried unplugging the idle stabilizer motor, setting idle speed by adjusting the air by pass valve in the air hose at stabilizer to obtain 900 rpm and reconnecting the stab. motor, will work for a short time. thought stab. motor was hanging up, cleaned with carb cleaner, air valve moves freely, one thing i did notice is when you unplug stab. motor when its at running temp. idle increases. am i using the wrong process to adjust curb idle?
joe