Chevrolet Repair: chevy 3.4 venture, truck mechanic, check fuel

Question
i have a 97 venture that just recently started having issues. 120000 mile on it and it started  acting like the fuel pump was failing,misisng dieing etc. i got it running almost made it home and the engine started dieseling rattling and died.it would restart and was missing and sounded like the timing was out of adjustment,then the bad part. after 5 min of this it wouldnt crank.got it home and the engine wont turn over by barring over on the crank or of the starter.full of oil and coolant didnt get hot or anything.poss timimg chain? unfourtnetly i am a truck mechanic and dont have a lot of car experience but i can fix just about anything. also has 2 codes p0172 and p0300.any help is appreciated. thanks!!!!!!

Answer
I would start off simple by charging the battery and then seeing if it will at least crank. If it cranks and then starts, check the charging system. The alternator could have failed and ran down the battery causing it to run rough and die.

If the engine now will crank but not start, Check fuel pressure, spark, injector pulse.

Get back to me after getting it cranking.