Now THAT is COOL! My wife is going to hate you, as now I want to buy one. And the price REALLY isn't that bad.

Yep, PCM controls ground side of the coil circuit. It OPENS the circuit to fire the coil.

Fuel pressure should remain steady. Bouncing that much at idle is most certainly NOT a good thing. Fuel pressure is not vacuum modulated, it is also NOT a return style system. Pump builds pressure, and is supposed to keep it right around 49 PSI. Why it would be bouncing that much is a mystery to me. Bad pump? Leaky injector(s)?

 

Well all apologies to your lady, but I'm a big proponent of having an oscilloscope, knowing what I know now. If I had this scope when I started, it would have paid for itself pretty quickly compared to how much time and money I've spent unnecessarily on parts and scratching my head. It's a whole new ball game.
There's some cheaper ones out there so shop around - maybe she'll hate a feller like me somewhat less...

As for grounds and fuel pressure, no dice.
Coil and battery grounds test good to the block and frame. PCM connectors all look clean and clear.
I've rechecked the fuel pressure with a better gauge and it's sittin pretty at 49 when primed, at idle, and at higher rpm, so scratch that.

I'm concerned now with the injector voltage spike. After some research, a 30V spike doesn't seem right... More head scratching...
Anyone out there know what a good voltage spike should look like on these factory 2nd gen injectors?

 

It's a 12 volt system, though the alternator likely puts out closer to 15....... spiking to 30 doesn't seem logical... but then, it's a dodge, so, logic doesn't really play a role here.....

Possible the probe is picking up a dirty signal?