I ended up replacing the #8 injector first. Then went on a trip from Oh to NC. Truck ran like **** thru the WV mountains @ 60-65 mph (3.73 rear). On the return trip I kept the speeds @ 70-80 and truck ran great with better power. I also thought the knocking noise at idle was injector knock on #8 but that sound remained after changing injector.
Also my mileage was better keeping the truck @ 2000 rpm.
After this trip I swapped out the PCM to see if it made a difference and it did not change the engine performance.
While replacing the injector I closed off the CCV connection between valve cover and intake. I routed the ventilation hose to a vented "crap can". I did notice moderate oil residue on the intake hose and turbo blades.
Running the truck at idle produces a good amount of blow by out of the hose.
How much is normal? It is enough to see a white smoke/steam plum out from under the truck.
So now I thinking the following:
1. Turbo boost not kicking up until 1900-2000 (38GTPR) causing low power?
2. Problem w/ #8 cylinder compression (due to rings or valve causing lots of blow by and knocking noise @ idle)
Thoughts? Is it easy to check compression? Seems like #2 would cause more serious issues with starting or smoking in exhaust.