What causes a 2004 Kia opimalx to die after apox. 10 miles?

Ok folks. I finally got it fixed. It turned out to be the small timing belt going to the balance shaft. It had a slight amount of slack in it. Once I tightened the tensioner pully for that belt, and I also sanded the disk that the crank position sensor reads, the car has gone a 1000 miles without any problems. I hope this helps anyone else that has had this problem. Thanks for everyones help