FORScan works just as good as most of the more expensive shop scanners out there, but there is a learning curve to it. On their forum page you can read on what adapter to get.
We also had a member do a pretty good write up on it
The information presented here describes how to use FORScan and FORScan Lite on our 7.3L trucks, to read diagnostic trouble codes, run self tests, and monitor important engine parameters. It will be under construction for a few days so I can add some pictures. Let me know if there is anything...
www.thedieselstop.com
It sounds more like a fuel problem. The fuel pump on these engines is a two stage pump. It pulls from the tank and sends fuel through the filter and back to the pump to pressurize it to send the fuel to the injectors. There are some that will have a restriction in the fuel lines from the pump where not enough fuel will be delivered. There is a plastic foot in the fuel tanks that will start to come apart and pieces of it will end up in the fuel lines and stick in the selector valve blocking the fuel flow.