A turbine engine combustion assembly including a casing, a combustion chamber, and at least one fuel injector. The combustion chamber includes an internal wall and an external wall extending one inside the other and connected by an annular chamber base wall. The external wall of the chamber is secured to an annular external wall of the casing. The injector is attached to the annular external wall of the casing and includes a fuel ignition enclosure extending inside the casing successively through openings in the casing wall and in the external wall before opening into the chamber. At least one wall of the ignition enclosure extending between the casing wall and the combustion chamber wall includes at least one air intake port. The external wall of the combustion chamber is solidly connected to a device for plugging the air intake port according to a thermal expansion state of the combustion chamber.