1999 Mitsubishi Mirage

I was driving home from the mall and my gas was low but i thought i had enough to make it home and to the gas station later but i broke down. I turned the car off and back on and i made it to the nearest gas station. I filled up my gas tank but after leaving the gas station my car cut off again. This happened a few times. I had my uncle look at it. I was low on oil & transmission fluid & i put both of those in & he put in new spark plugs but when we tried to start it after that it wouldnt cut on. He took out my battery and put in his & it still wouldnt work so he put in another starter & it still wouldnt work. He worked on it some more & got it to work but said it cut off on him again. I dont know what is wrong with it & my uncle thinks it might be the fuel pump or bad fuel. What do you think?