Many problems, especially hard starts, on the 6.0L's can be attributed to a poorly functioning FICM. The FICM basically controls the firing of the injectors, and when (and we mean WHEN) the board begins to fail and lose voltage (below factory 48 volts), it will cause various run-time issues, hard starts, excessive smoke, and the list goes on. BD-Power has the fix for this with their own 58 Volt FICM in which they clean, repair, and reassemble original 48 volt versions. Each unit is gone through 100% to eliminate any intermittent failures that can arise from other companies that only replace what is damaged at the time of inspection.