1st post guys. My early 03 6.0 dies under a load. It starts idles and revs fine but when I put it in gear it looses rpms and then dies. I have had every sensor known to man replaced at least twice. I have had injector trouble, computer trouble, and electrical trouble. I am out of warranty and would like to fix it myself. I am thinking about a tuner as well as new injectors. I have searched this forum for days now and found lots of information. My problem is the more I read the more I am confused about where to start. I also have an 04 6.0 that has never given my trouble and I pull a big gooseneck around with it nearly every day. Any help would be great.

 

I would check the fuel filters for clogging, then check fuel pressure.

 

Changed filters and checked pressure. No change. I really need some ideas.

 

Allright, check this out. I just connected a code reader up to it and the truck won't even recognize one being plugged in to it. I checked my other trucks with the same device and it works fine. Now what?

 

You could have a bad pcm or a bad vref issue, also if your code reader can not "talk" to the pcm you either have a bad power/ground to pcm or you network wires to the dlc are bad. Pull your owners manual and start by checking ALL fuses and check the PCM power relay.

 

Thanks, jboczar, I had a blown fuse to the OBD. Now the reader says no link. And of course the truck still won't start. I will try the other things as well as the vref.

 

I have no codes showing. I guess it is headed for the shop. Who has the best Powerstroke guys in Dallas?

 

Get hold of JDadamsjr on this site. He lives in Dallas and should be able to help you out.

 

Now I am thinking hpop or ficm???

 

I think a failing FICM would throw some kind of a code, but not necessarily. HPOP you could have a leak and you could check that yourself. 03/04's HPOP's were problematic. I noticed you said you checked your fuel pressure. Do you remember what it was?