2002 Cadillac Escalade gas i think

i got a 2002 escalde the start and then well go to about 1000 rpm and die slow i think it might be a fual pump but i dont know it is hade to say i well start but then if i pump the gas it well alow me to go up in rpm but it just dies after that and sometimes when i press the gas it well just die mybe someone can give me some insight on this