300 E Quits at various conditions

[towjoe42]

I had this car for four years and it started to quit at Idle, driving on the freeway at 120mph.Only kidding quits at any speed and condition.
It ran so good when I got it, it passed smog right away. Funny two years later it failed and the smog shop said there was no catalytic converter. I said want to hear a funny story? It passed smog two years ago without a catalytic converter at your shop!
After 3 repair shops and $800 dollars later it still quits.
Replaced;
New battery.
Charge control relay at a Mercedes dealer,
Fuel pump-two times.
Fuel pump relay.
Tune up and wires.
Complete fuel distributor.
I almost ran out of patience. Thanks for any ideas to fix it.