I don't know what has help

Hi everyone, I have a 1985 Renault 18 GTX, but it has a problem. I start it and wait 10 or 15 minutes for it to warm up, and then when I let off the gas to shift gears, it stalls.
What could it be? It also happens when I brake at traffic lights; basically, I can't let off the gas for long because it stalls.
The car is a 2-liter gasoline engine.

Hi,
you can check that the fuel filter isn't clogged, or give it a little more fuel for idling; it's a small screw on the carburetor (use a small flathead screwdriver).

It's carbureted, so you'll have to check if it has an electronic choke, which controls the idle. You can leave it revving a little higher to prevent stalling, but I recommend visually inspecting the vacuum hoses going to the carburetor. If they're okay, service the carburetor. If it still doesn't work, check the vehicle's electrical system. Do you have an electric or mechanical fuel pump?