For the past 4 weeks when I go to start my 99 Chevy Lumina with 118,000 miles on it I put the key in start her up the radio & lights come up but sometimes she dies? If I give her a little gas she is fine..what could be causing this? I don't have a lot of money to run back and forth to an auto shop. I was thinking fuel pump or fuel line. When she is driving she runs just fine.