Car will start but won't stay running

if no error on sensors you have problem with the pump electric feeding you can know if override this and give pump direct electricity and the car work longer but if you override you have to open close circuit to maintain fuel pressure to not be over or less 3 second on 1 second off if on ideal. if the problem exist with the over ride check the fuel line pressure, then check the injection system and air system.

It's usually best to have things operate as they were designed , check the ground at the fuel pump , it's sending unit may be bad , when you hit the key the pump primes the system till the motor starts then the regular circuit takes over , check for pump relays and power at the tank disconnect

I have a Mercedes 2011 550, it starts but does not contiune to run, also there a little smoke that's comes out. Want stay running