sounds like the same symtptoms of my 95 c200.

surging idle when hot....
missing when cold...

I replaced OVP, throttle actuator, coolant temp, air temp and wiring harness.

Still does it, its at the dealers now. Theyve stated that there are voltage drops at the ECU - not sure what would do this.

Along with MAS air above upper limit (this has been swapped from another car and no go!)