Possible Fuel Problems

My 1996 BMW 316i (compact) began to sputter every once in a while... Sporadically over the past month. Today, it started fine, and then when I went to drive away, it began to lose power. As I put the car in neutral and pressed the gas in high RPS to warm up the car; the car began to act normally. Once I started driving again, it continued to sputter, and then the problem went away. Upon driving around 40-60 miles per hour, the car began to lose power again, but quickly regained speed. It now seems as though, I have to warm up the car for 10-15 minutes before I drive, then it will act normal. However, when I go to accelerate and change gears... The car sputters for a second then catches up again.