If the fuel tank is below a quarter of a tank then the fuel pump is having a hard time picking the fuel up because the fuel is sloshing to one side of the tank,and also the fuel filter could be clogged up. Check with the parts store to see if this car has a fuel filter mounted on the rail or inside the tank,if it has one on the rail then change it out first and that just may solve the problem instantly,this is what I would do ,,,,,,,,,,,,,,,,,,,,,,,