1996 6.5 hard starting and in limp mode
 

so ive had my truck for about two weeks now and when i first got it it was a little hard to start but since my fuel gelled a couple of days ago it through an engine could (p0370 and p0251) its in limp mode now but if anyone has experienced this please give me some ideas of what i could do.... any advice will help im lost.

For future reference... http://www.troublecodes.net/GM/96_65.shtml codes for your engine.

Codes currently being thrown....
P0370 ..... Timing Reference High Resolution
P0251 ..... Injection Pump Cam System

Probably needs the timing checked. and / or reset

Is there a thread on how to do the timing or should I just take it to shop and let them handle it?