I replaced the MAF today and no change. Starts instantly cold races for a second and then idles down. Runs smoothly for a minute and then starts to run a little rough and then after a couple of minutes starts to surge badly.

The idle slows down to 600 rpm.

I used MAF sensor cleaner on the air temp sensor. Checked that the boot connections were tight. Wiggled all the harnesses and connections and vacuum lines again.

I sprayed Starter Fluid all around and it did seem to smooth out and pickup speed slightly when sprayed around the throttle body. I wiggled everything I could find and I can't figure it out where or why it would affect the throttle body.

I did buy a used throttle body off ebay for $286 from a supposedly reputable Mercedes parts guy. It looks beautiful but the harness has been cut open and there is no insulation visible. just powder. I was thinking of keeping it and trying to rewire it but my hands shake so bad I don't know if I'm able to solder it.