It would have been very easy to slag the tech for his ability or lack thereof, but having taken the time to understand and see what he went thru.... well, what can you say.
In retrospect, a major factor that may have prolonged the whole issue, was the fact that the car was not symptomatic during the first couple of visits when the tech was working on it. SteveBfl made this point earlier in the thread.
Suprisingly enough, I did not know this, because the car had been dropped off, and I was off tending to business. I assumed that the car continued to act up even after a cooldown period.
Once I was aware of this and brought the car in ""hot", then there were real time readings that at least got us going in the right direction.
The real break came on the last visit when the MAF voltages were different, even after MAF and ECU swaps, and that the higher voltage (1.8 vs 1.2) remained on the LH2SFI side.
During the last manifestation of the symptoms, the car acted vastly differently than the other times.....the economy meter swung wildly from side to side, the engine reacted as if the accelerator was being released and floored on an semi regular basis.
I have spent so much time in the shop with the tech, there was a standing joke that I was on the payroll. But I didn't mind being a gopher, and boy did I learn alot about the MB star diagnostics and the pinout box, how to use it and decipher MB's manuals.
Yes, I got dirty stripping harness as well, but that's why we love our Benz's, right?
I'm still having a hard time believing the wacky readings that this issue gave, and some of the absolutely nonsensical cause and effects that one component can do to effect the other components.
But, thinking about the 5 (I think) bare wires at the MAF connector shorting out with each other on some irregular basis based on whatever whim the vibrations of the car and engine would present....egad.
When I get the car back, I'll drive it for a while, ensure that it is cured of it's epileptic tendencies, and then the techs, service reps, and I will empty a bottle of champagne. (maybe 2, well, maybe...)
A mercedes is an inanimate object and therefore must respond to logic and reason.