Ok, here's something I've never seen. I installed the new Bosch 68875 fuel pump back on the truck this morning. I just started it up and ran it to warm up. When I rev up the engine it is smoking like the rings are bypassing. But all I have done is replaced the fuel pump. Also, when had this Bosch off the truck to look at it , it had a lot of oil drain out of it where the lever comes out of the housing, much more than the pump it replaced. So, my logical analysis indicates that this pump is sucking oil out of the engine and burning it. This would also explain why the plugs are all black and why it ran like crap. It's oil fouling the plugs??
Unreal.
The old fuel pump is leaking a little gas externally and that is why I replaced it.