HI , YOU WILL FIND THAT THAT IAC VALVE WORKS ALL THE TIME, IT WILL BE SET AT A HIGHER SETTING WHEN COLD BY WAY OF A NTC INPUT TO ECU. ALSO AC INPUT TO ECU ECU OPENS IAC TO MAKE UP FOR AC LOAD. THE FUEL SHUT OFF IS DONE BY THE CONTROL VALVE ON THE FUEL HEAD. HAS BEEN A MOST DEPENDABLE SYSTEM ON MY AUDI QUATTRO JIM CRANCE COLORADO SPRINGS COLORADO