What caused my 20 13 forester to start and stop?

The reason of carbon deposition is the cold start, flameout or jitter of the car. Carbon deposition generally appears on the inner wall of throttle valve, intake valve head, intake port, piston top and combustion chamber. Excessive carbon deposition will lead to insufficient air intake, difficult starting or easy flameout at idle speed. After the water temperature reaches the normal working temperature of the engine, the throttle valve is opened too much to exceed the normal value.