agregersen

so my truck has a pretty bad miss between 2000 and 3000 rpm,started after i put in the flux 2's. so i thought it was draining the rail, i got a arson 3 kit and put it in,and nothing changed according to the gauge the rail pressure is solid.it misses,pops,and studders and smokes alot when it does it,also it seems to do it more when the engine is cold,and only does it when im hard on the throttle, any other time it runs strong.anybody got any ideas, i dont know were else to look. thanks