Those checked out fine. Decided I didn't want to chase an electrical gremlin so I brought it in.


It appears the issue was a wire to the cam position sensor was rubbing and wore through the insulation. The mechanic removed the bad section and it appears everything is back to normal. The voltage acts as I used to remember it and doesn't drop below 14. Drove 40 highway miles and there were no issues. I'm hoping that solves it.


Now to follow the oil consumption...

 

I have a similar problem. No oil pressure after engine warms up. Then an engine knocking noise. Suspect something serious.

 

Knocking is a sure sign something isn't right...
check the basics, make sure the oil level is correct, might also consider changing the oil filter out just in case its blockage...
The next step is to get that oil pressure checked with a gauge so you can see what is going on....

 

Just got it back from the shop. They said all they did was flush out the oil system. How I'm not so sure but all's they said was they ran a cleaner through the oil system, then put fresh 10/30 in. They suspected the oil from this car's previous owner was not taken care of and was slugged up. When the engine heated to a certain temp, the oil sending unit had trouble sending oil back through the system. Air bubbles will end up going instead and the noise that sounded like knocking was actually an effect of air into the lifters??

Whatever they did, it worked. Just ran the car a couple hundred miles over the weekend and the oil pressure and engine behaved just fine.

 

Excellent! thanks for the follow up