Trust me, I'm regretting that particular move.

Try changing the oil and putting some Rev-X in maybe?

Ok, so I pulled the IPR and found a small piece of plastic lodged in the screen. The screen is somewhat collapsed now with a hole in it. I'm guessing the plastic came from the filter housing tube. Last year a replaced it because the relief button on top was broken. I guess I will by another IPR and see if that corrects the problem.

Ok, the plastic was actually a piece of "O" ring logged into the IPR. I removed the HPOP and found the "O" ring under the pump was coming apart. Back together and running now. Thanks again for all your help and suggestions.

HPOP was a bad idea for these trucks, just too many problematic things can go wrong

It is and it isn't. HEUI is a work of art in it's own regard, but they can and do have problems. I'd rather have an oil leak and the truck not run great than have a commonrail and worry about an injector sticking open and the CP3 filling my motor and burning a hole in the piston. Far cheaper to replace a couple o-rings than it is to rebuild a motor.

HAHAHA 6.4=doom.

all they had to do was make the stand pipes thread into the branch tubes or run external lines like the 7.3 had to each head...

HEUI is not only used by ford/navistar theres a few big rig engines that use it...
And theres a reason why our remanned injectors are being rebuilt by cat...