Yes I agree there seems to be an electrical issue at hand. I even noticed my headlights dimming on me a few nights ago. I can't remember the exact scenario, but they just dimmed for a second or two while I was starting up or something. Not only that but according to a service log that was kept by the previous owners, there was a history of continual 'Electrical' problems. Details were not given.
Which brings me to an experience I wanted to bring up anyways which is very likely the cause. When I was reconditioning the ECU, I think I messed something up! Man what an idiot I am lol. It just now dawned on me that I did it Wrong! I disconnected the Positive cable from the battery as written, but I misinterpreted the next part! Instead of connecting that Positive Cable to ground, I ran a jumper from the Positive Battery Post to ground!!! I knew in my mind that that was a short circuit but, at the time that's how I comprehended the instructions! Stupid on my part!
So... Did I potentially fry my computer and/or ruin my battery?
I suppose a proper ECU conditioning should be performed again ?
Another thing I didn't yet mention is: One evening all was fine, I stopped to visit a friend, then later that night as I started up the car to leave, all of a sudden I lost the the 'Groove' response and the vehicle acted sluggish & wimpy like it had prior to the groove.
Hmm, I'm pretty sure that's the same night I noticed the headlights dimming.
That's interesting to me, how can RPM be affected by electrical loss. Not enough spark for combustion?
Man this is turning out to be a huge crash course in learning about vehicles, Wow!
I think I'm experiencing just about everything Lol. That's ok, as long as it works in the end.
In the meantime I will take your advice Ron and document voltage.
I'll have to re-check later how the vacuum gauge needle behaves on Booster. I wasn't close enough to the gauge when I was applying the brakes. If it was moving at all it must've been vibrating very slightly because I couldn't tell from the distance and view I was at.
However, earlier on when I was vac gauging the Intake Manifold while idling, the needle was indeed vibrating so quickly that it looked blurry. I'd say a total range of ~1. Is that Normal?
Also the vacuum was only reading ~21. Shouldn't it be higher because of the Groove?
Last note: Ron, the vacuum did indeed drop when I pressed down on the brakes, as did the RPM, BUT, the vacuum did not return when I let up off the brakes.