2000 Camaro still having starting problems

I BOUGHT THIS CAR IN MARCH, IT HAS 105255 MILES. V6 ENGINE AUTOMATIC, FIRST IT WAS TRYING TO TURN OVER BUT WON'T CATCH. THE FUEL PUMP AND RELAY, FILTER, REPLACED, 3 WEEKS LATER IT WON'T START, TOW IT TO DEALERSHIP, IT WAS AN INGITION RELAY, REPLACED, 1 WEEK LATER IT WON'T START, IT WAS THE COMPLETE INGITION SYSTEM REPLACED TWO NEW KEYS AND KEYLESS ENTRY WAS PURCHASED. ALL AT THE DEALERSHIP. TODAY AFTER 5 DAYS OF GETTING CAR BACK. IT WON'T START AGAIN. DEALERSHIP HAS IT AGAIN. THEY DON'T HAVE A CLUE, NO FAULTS ARE SHOWING UP OR CODES, PLEASE HELP, I'VE SPENT OVER $2500 AND I STILL CAN'T DRIVE CAR. WHEN YOU TURN THE SWITCH AT THE FIRST POINT ALL LIGHTS COME ON AS IF IT;S GOING TO START, SECOND POINT IT HAS NOTHING. GOT IT TO DEALERSHIP, AND IT STARTED FINE, DON'T KNOW WHAT ELSE TO DO, CAR HAS LEFT ME STRANDED MORE THAN I'VE DRIVEN IT.