Because the engine is too hot to continue cycling correctly without the pistons "sticking" against the side of the cylinders, causing them to slow down or even stop moving in extreme cases. buy some antifreeze
most likely you need to replace te heater core.generally i if the leak is on engine you wont smell it in the car
clean rad & cond at the car wash see if that wont help
Each car overheats at a different temperature you need to look up and find out on the internet
How do you know that it is your car?
It wont start
Your car wont start. lol
What have you welded ?
use jumpers
YES
how does it stall if it wont start?
Don’t no
car wont start