Volosong, Is this the great Enrique who's stumped by your car's symptoms? I didn't think that was supposed to happen to him.

Parts of your symptoms sound familiar. My 103 lately idles and runs rough at low speed after prolonged high-speed driving. Otherwise, the motor runs great, idles great, accelerates great, only not after prolonged high-speed driving. No CEL. I've hauled out the multimeter and done some basic testing, and I haven't figured it out. So, tomorrow, it's off to my indy. Leading suspects are:
1) OVP (mine's nearly brand new, and I can't see anything obvious wrong with it, and the ABS lamp is not on and the fuse looks good)
2) EHA (Y1)
3) EZL/CIS temp sensor (B11/2)
4) IACV (Y6)
5) throttle valve switch (S29 and S29/2), and
6) airflow position sensor (B2).
While we're at it, we'll check out the coil (it's the original). I don't even want to think about the possibility that it's the KE or EZL control units. So keep us updated on what you find, and I'll do the same.

__________________
1988 California version 260E (W124)
Anthracite Grey/Palomino
Owned since new and still going strong and smooth
MBCA member

Past Mercedes-Benz:
1986 190E Baby Benz
1967 230 Inherited from mom when she downsized
1959 220S Introduced me to the joys of keepin' 'em goin'

There are only 10 kinds of people in the world--those who understand binary and those who don't