I would suggest you rethread the machine and then sew on another piece of fabric. If it sews for at least a yard and the stitch pattern, tension, etc is excellent, then try the quilt again. If the problem occurs with the quilt, then you know something connected with the quilt is wrong. The speed of moving the fabric, the feed dog position, the walking foot, the tension for holding thick fabric or the tension on the thread. If it works fine with regular fabric, the problem is probably in the way you are manipulating the quilt through and under your presser foot. I'm not sure I'm expressing this plainly. Good luck.