I'M NOT SURE WHAT YOUR AIR INTAKE SYSYEM LOOKS LIKE, BUT I HAD A SIMILAR PROB. ON MY 97 SUBARU. I WOULD START IT UP AND WHEN IN CAME DOWN TO IDLE IT WOULD JUST DIE. IT TURNED OUT TO BE A HOSE (1" ID) THAT CAME DETATCHED ON THE UNDERSIDE OF AIR INTAKE TUBE. MAYBE LOOK FOR SOMETHING LIKE THAT. IT PROVIDED SOME KIND OF VACCUUM TO THE MANIFOLD, AND TOOK ME WAY TOO LONG TO FIND, YOU KNOW ONE OF THOSE SIMPLE, OVERLOOKED THINGS.