[Dave at Pelican Parts]

Depending on how cool the AAR gets, it would have some effect on an engine that's been sitting for a while. The AAR is controlled by a bi-metal spring, which moves the valve based solely on its temperature. The AAR also has a heating element inside of it to change the temperature of the spring at a given rate. (That's why the valve will still work, but very slowly, when it's unplugged.)

--DD