He continued to serve along the Kokoda Track and at Buna–Gona, until he was evacuated sick on 22 December. He was promoted to Captain effective 16 January 1943. After leave in Australia, Kienzle was posted to Soputa as OC ANGAU Labour Mambare District. Kienzle applied to join the AIF for deployment overseas with the 7th Division. His application was declined in a reply dated 7 April 1944, which, ironically observed that he was too old to face the rigors of tropical warfare. He was, however, granted leave to be identified as a member of the AIF, in recognition of his service. He was discharged in December 1945.