hey every im stuck on whats wrong with this truck. the other day i was driving home from work and all of a sudden it started running rough and then the check engine light started flashing. i got it home and parked it for a coupla hours and then went out side to start it and it had a hard time starting and was still running rough. i checked the codes and gotta P0300 after i checked the codes it wont start at all it cranks fine its just not firing up it sounds like it wants to turn over but it just wont. iv checked the spark plugs and changed them i checked the coil packs and there fine it getting fuel and the headgasket isnt blown and all the fuses and relays a good. so im stuck and dont know what to look at i was thinking it could be the crankshaft positioning sensor. or i got told the timing could be out.
any help would be great cause im stuck

 

do a full tune up with the plug and plug wires and distributor cap and rotor , etc

 

Id try the crank sensor

 

im gunna check the crank shaft position sensor i got a feeling that thats what it could be.
i changed the spark plugs in it and the the coil packs do not need to be changed its getting spark and fuel.