I WENT TO START MY 1997 CHEVY G1500 VAN AND IT WONT START. IT CRANKS BUT THAT IS IT. MY NEXT DOOR NEIGHBOR SPRAYED SOMETHING UNDER THE AIR FILTER AND IT STARTED AND THEN IT DIED. MY HUSBAND SAID IT IS THE FUEL PUMP, BUT I'VE READ IT COULD BE THE RELAY. IS THERE A WAY YOU CAN TELL IF ITS THE RELAY AND NOT THE FUEL PUMP? OR DO YOU HAVE TO CHANGE THE RELAY AND IF IT STILL DOESNT WORK IT IS THE FUEL PUMP?