since it fades w/ the key on im not sure, the pump comes on to prime the system w/ the key, but then you can hear it go off, and it doesnt come back on again in your case, im not sure if this is by design or not, but the bleeding off w/o the pump on means that the check valve is bad and not closing (checkvalve = anti-drainback valve)

have you done the fuel pressure test with the throttle opened up some to see if it can hold pressure under high fuel flow situations?

 

I haven't tried with any throttle. I can try that.

Here is something new.....This morning, when pulling out of the driveway, the Durango kinda stuttered a little bit. Wasn't bad, and only did it for like 10 seconds. It was fine after that. CEL isn't back yet since the last reset, but I'd expect it soon.