Defective injection pump?

[Goose57]

Hi all it’s been awhile. I believe I have a remand bad pump on a new engine installation. Got it from QS tuning. Installed the remand pump hard starting, missing, smoke and cylinder balance codes on all 8 cylinders.
https://youtu.be/2aYBAkaTQ_M?si=EdgbYUpEP8R6RO5u

put my original pump back on and it took care of the problems and no codes.
https://youtu.be/jSwnsfMQyUU?si=in5OFlIfXbrblmC7
Both pump installations timing was set within specifications and did nothing different to the engine between pump installations.
The bad thing I bough the remand pump last year and QS tuning said they could check it $500 but it is technically out of warranty. He did say after they check it he might be able to work w/ me. In the mean time I found this bulletin go to the last page sec 5 engine diagnosis. What are you guy’s opinions on this?
thanks guys.

https://www.dieselplace.com/attachments/stanadyne-ds4-service-bulletin-sb-500r2-pdf.380602/
I will have to also change my signature.

[More Power]

Does the timing stepper motor assembly on the passenger side of the pump look ok, connector plugged in? You could also disconnect the timing stepper motor's mechanical linkage, and then try to rotate the mechanism on the pump by hand to see if the cross shaft moves ok.

How'd you rotate the engine to allow access to the 3 pump gear bolts?

I saw some blow-by in the second video that seems out of the ordinary (coming out of the valve cover where the CDR is normally located), though it wouldn't necessarily have a bearing on your current injection pump problem.

Jim