Low engine speed during high pressure test

[Rounded_nut]

I ran the high pressure leak down test again this morning and the pressure went to about 29k, but instead of a little extra noise from the fuel pump it was a fair bit louder and then it aborted the test due to low engine speed. I was at a normal idle and this hasn't happened before, cylinder cut out looked good, even running on the one cylinder the ecm says has a bad spill valve (number 6). Can anyone say if this new development is pointing to something other than a bad injector? I did have number 6 injector replaced about 2 years ago, can't remember if it was a reman or new, just that it came from peterbilt of Denver. I'm trying to keep from blowing money at the stealershit, I'm about 50 miles south of Witchita Kansas.

Thanks!