My 2003 surges at driving speeds. It runs fine at idle and no starting problems. The surge is very slight but noticeable and just started a week ago. About a month ago I put in a set of dynamite diesel stock injectors and the hard start when cold situation went away. I have a fass fuel system so I don't think that is the problem. I have thought about changing the FCA- fuel control actuator. From what I have read this might solve the problem. Also I put on a new throttle position sensor about 2 years ago. Let me know what you guys think.