Truck keeps cranking wont start
 

2004 1/2 f350 extended cab 6.0
no engine mods
changed fuel filters (dont know the kind friends diesel) took it for a ride blew black smoke when opened up and then died.
its used to for pretty much everything never beat
the issue started after the fuel filters were changed. took it for a ride and when he got on to it, it blew black smoke, wouldnt come out of second, lugged down and died. the only code its reading is p113. Its got brand new batterys and when he cranks it, it sounds like the batterys are weak but they got 12 volts to them and it just sounds weak cranking but keeps cranking and cranking. can some one help me i need some ideas on this.

How many miles on the truck? 12 volts isn't really high... unless you have the batteries disconnected when reading that, with them hooked up together it should be closer to 14V. If you figure a 2-3V drop when cranking... and the PCM shuts off at 9V....

I'd get the batteries load tested at the local auto parts store. If one is bad, replace both. I'd also test the FICM. You can find the test procedure at the top of the 6.0 page.

I have a feeling it might be more like the HPOP is dead, but these things are free to check first and a good place to start, after that you're going to need a scanner to hook it up to.

Can you double check on that code, p113 is not a full code.