Automotive Forums

hi i´m new in here, and from denmark, so sorry for my bad spelling in english i´m an automechanic and works with us truks daily, so i know a little abuot them, and have ben doing that for the last 8 years.
i have a problem with my 03 2500 RAM 5.9 diesel.
The enginge have ben running hard for som time now, but with no drivability problems, until it died on me a little while ago. I found out that the lift pump had died, so i replaced it with the original replacement kit. then it could start again.
now the problem is, *** following.
when i start the engine it set´s DTC P0251 (CP3 pump regulator control) right away and P0088 (Fuel rail pressure signal is above max limit) after a while. when those are set it only runs with 48-50% power. If i turn on the ignition (without crankig) erase the dtc´s and crank the engine for start (without back cykling the key first) it does´nt set the dtc and run´s (still noisy) wihtout lack of power and it does´nt set the dtc until i turn it off and start´s i again.
If i (with the drbIII) watch´s the fuel set point, it says about 36000 kpa at idle speed, and the actual presure is about 160000 kpa.  I´ve messured all the wirrins, solonoids, valves, actutors, ecm, pcm and cheked for leeks in the system, and it all works according to dodge´s own repair/dianostics prcedure schematics.
I´ve changed the overflow vale, limit pressure valve, the fca, fuel rail presure sensor, flashed the ecm with the newest update´s, replaced the C2 wiring harnes on the ecm (had doubt about the wirring connections). changed fuel filter.
I hope that there is anyone that have just a little idea or clue about what could be wrong. thanks