To follow up, I installed a new set of Bosch plugs and reinstalled the OE rotors and the problem is so bad that the car will not stay running. There are no codes stored and no check engine light coming on. I am going to install 2 new MB rotors today and see what happens.
I could sure use some help trying to figure this out. I had a Corvette that the dealer couldn't fix that was doing something simular. I was able to find an idle air control that was bad that would never set a code but this is driving me nuts.
still needing pain relief
92 500E 90K miles stock less AMG chip
73 Datsun 240Z, 74 260Z, and a 75 280Z 2+2