I have a 90 190E 2.3 (8V) with 176K. Occasionally, I get a really low idle (400-500 rpm) that will usually stabilize if I press the brake pedal a few times. It has done this periodically for over 2 years, and I have put 2 alternators on the car. The original one lasted from new (I presume) until last summer. I bought the Advance Auto rebuilt (needed quickly and was my only weekend option here) and it lasted until 2 weeks ago. The other thing I just noticed is that the ABS light does not light up when I turn the key switch on - I'm thinking someone may have had trouble with the OVP and took the bulb out or the bulb burned out from being on. And one other thing, sometimes the throttle linkage will not engage the microswitch - manually pressing this will stabilize a low idle as well (although sometimes the idle will be near-perfect without the microswitch engaged and engaging it will just trim the idle a little more smooth). Any ideas guys?