Everyone, including me, is speculating because its not our car, but it sounds like you might have two problems that both might have been brought on by a poorly processed batch of WVO. You might have sent a marginal injector over the edge and that would contribute to the noise and the hard start. But the fuel starvation issue sounds like filter or tank issues that could be WVO related. Check previous suggestions on isolating the clack if its an injector.

If you have been blending WVO in your diesel tank, then poly likely has formed in your tank and may have clogged the intake. WVO should not be put in stock metal tanks. I say this from personal experience in addition to consensus. Do the fuel delivery/return switch to check on a full tank of diesel, and consider cleaning the intake or pulling the tank and cleaning everything if that suggests clogging. Installing fuel pressure gauge is very helpful in sorting things like this out. My opinion is that if the intake is clogged, its worth the extra effort to pull the tank and have it cleaned, especially if you intend to continue blending WVO and diesel.

Oil burning at 247K...not surprising. Perhaps a head rebuild is in your future.

Another unlikely possibility is the overflow/pressure relief valve on the return side of the IP, but I've never heard of it causing acute symptoms in a 616/617(though it does on the similarly designed older Cummins). The clacking definitely sounds like an injector.

Water?...I would check the contents of the filter to see if you introduced any water. Probably not, but would be useful to know.

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1983 CD
1958 Studebaker Packard (being resuscitated)