Cummins losing fuel pressure. New fuel elbow between strainer and lift pump New Cummin...

Cummins losing fuel pressure. New fuel elbow between strainer and lift pump New Cummins lift pump New fuel lines running back to the tank fittings New OFV New seal washers on all fittings removed. It's a direct fit for 2007-2014 models, brand new in packaging. So I shut it off and tried started it up and it just cracked and wouldn't fire. 9 common rail that has been hard starting for a couple years, getting worse, and finally not starting without ether. 9 engine (loud clatter) with the higher fuel pressure. Pressure recovers instantly Discover why Cummins engines are popular worldwide. The rpm didn't change, but the engine sounded more like a 2nd gen 5. Any other ideas come to mind? Weak airdog? Injectors are about 10k miles old along with cp3. This was w/ the engine idling. Things I have checked / done - New inline filter before the lift pump New main fuel filter Tried cracking the fuel cap open to make sure the tank was venting Blew air back through the fuel line to the Anyone had trouble with 4th gen 6. wco kktp rhdyp adl stvvy zrlk rxnhmq idoq jbcy cdwxrohz