What's the name of this part?

[yjamous]

Hi everyone

I've a Mercedes E220, European, Model 1993. There's a part that the mechanic said I need to change since the engine turns off if I don't keep pressing on the fuel paddle. Honestly, I always prefer to check with this Forum before listening to any mechanic since there're really professional people here.

I've attached pictures for this part.
I've in fact 3 questions:
1) Does this part cause the above symptom?
2) What is the name of this part?
3) Does anyone know an estimate for such part?
4) Does anyone know a website that sells this part?

I would appreciate any feedback

The chase number of my car is WBD123021B939455