Thanks all, I’m going to check my alternator belt tension tomorrow and report back my findings.
I had assumed the voltage regulator because the problems arose shortly after I improperly jumped another car (black cable on negative battery post) sorry, I should’ve mentioned that earlier.

Regarding the fuel line, here’s the background:
I have been trying to figure out an issue with the engine occasionally stumbling during cold start. Glow plug system is working perfect, new glow plugs too. Valve adjustment just done.
I had read somewhere else (can’t find it now) that another person had similar issues and discovered it was a crack in an injector line. So, i thought I’d test this idea by cracking all the lines while the engine is running. All lines start spitting fuel immediately, except #4. I’ll crack the line, nothing happens, bubbles, then squirting. The car will run a little smoother too if I do this little dance.

Then, I shut off and restart, everything starts over again. My thought is this may mean a tiny crack in the line, or perhaps the fittings aren’t sealing. I’ve inspected visually and found nothing, and it doesn’t leak fuel....

Does that make sense?