Timing problems 5.7 VORTEC HELP!!!!!

[old Chevy guy]

I have a 2001 3500 cube truck with a 5.7 vortec.For a long time the check engine light comes on going up big hills.For a couple of weeks its been starting funny sometimes kicking back or binding up like the timing is to advanced.Then the other day it wouldent start at all, almost but not ,binding up real bad.I tried replacing the pickup in the distributer but no good.I knew the timing is not really ajustable but I moved it anyway in desperation, then it stopped binding and finnally started altho it was flooded from trying to start for so long.when it got home it started good and for two days since and no light. Did I fix it or postpone A bigger problem? Anybody have any advice or a similer situation? Does anyone know anything about the timing at all?Ive heard some diffrent stories and I dont know much about this truck at all,I finally started to figure out the 5.7 TBI s that we had and then I bought this,Probly figure it out in time to get rid of it also.My 71 is so much easier to get along with!