Brother of The Benz, Alon
Your chasing your tail Alon.
The octane rating wil NOT create the condition your engine is having.
With your tank near empty your fuel pump may have drawn the accumlated crude from the bottum of the tank. This could explain why the Premium fuel momentarily corrected the provlem.
Add the Fuel Tank Cleaner as suggested.
You said you see "BLACK" smoke. This indicates an over rich fuel mixture.
Changing electronic components wholesale will only give you new parts and not address the problem.
Not to make you feel bad, but my 1987 300E with 176,000 miles still has the original distributor cap and rotor.
If the problem was with the fuel filtering, the engine would not recover after running poorly. The fuel filter(s) are located under the chassis behind a protection panel usely on the right side.
Alon you may have have numerous problems, but replacing parts without justification is not the way to go.
Address the dirty fuel approach first.
Happy Trails Beep Beep from The Spiderman in Houston!!!