A method for testing a memory device. The method comprises delivering a first substance to a cylinder of the engine from a first injector; delivering a second substance to the cylinder of the engine from a second injector, where the second substance has a greater heat of vaporization than the first substance; and increasing injection of the second substance responsive to an exhaust over-temperature condition. The power saving unit saves power communicated between the setting mechanism and the rotating member engaging member when the setting mechanism attempts to move the rotating member engaging member into the rotating member engaging position and the rotating member engaging member encounters a force that resists the rotating member engaging member being in the rotating member engaging position. The VDS has a P-code data file for holding the P-code, a virus definition file for holding signatures of known viruses, and an engine for controlling the VDS. In addition, methyl salicylate does not leave behind an unpleasant after taste.