Was doing some browsing and I thought I'd share. The last paragraph that talks about 6.0 injectors is pretty interesting. I wonder with FICM tuning you get this back?
Early 6.0's had a function similar to the split shot injection of the 7.3's called pilot injection. Instead of being a hydro/mechanical action, however, on each compression stoke the FICM would energize the injector once to start combustion, turn the injector off, then energize it again. This was to provide less engine noise and improved emissions. But, this programming caused timing problems on hot restarts, resulting in rough running and loping, so the strategy was programmed out in later calibrations.