You can always fix this issue with programming. Simply program in new idle points (servo's will never move below the programmed idle points while syncronizing). You may also want to program new sync points (this is the throttle position the device starts synchronizing). The device does nothing except act as a "Y" cable if you are below the sync point. The other possibility is if you have a loose glowplug clip vibrating (or an unshielded spark plug wire), it can cause glitches while starting the engine.