Diesel Bombers - Injection Pump Help....

My lift pump went bad so in lieu of going back with O.E.M. I chose to go with the AirDog II system. My buddy and I removed the Bed with the help of my tractor and got the unit mounted and wired in correctly. I was hoping I would'nt have a CP3 IP problem so I cranked the truck up and it started up fine and under no load my rail pressure gauge would climb to 18-19K. We jumped in to give the truck a shakedown run and when I pulled out I brought it up to about 30 mph and tried to accelerate and nothing, foot on the floor no speed change but the rail pressure dropped to about 3-4K. I bought a new FCA, High Pressure Fitting, and Ported Gear Pump from II. My thought process was that if I in fact have fuel in the IP then my plungers are somewhat lubricated. Well needless to say after putting the new parts on listed above I cranked the truck up and it ran great. Pulled out of the driveway and matted it, rail pressure 20k blew it out and it was responding great. I get a mile down the road and all of a sudden rail pressure drops to 3k and EGT's shoot up and truck coolant temp shoots to 244 Deg F. limped it home and now I am not sure what to do.

Any ideas would be great, let me know what you think.:argh: