Check these things:
1: On the back of the CP3 there is a plug in sensor FCA unplug it and start it what does it do?

2: What is your fuel pressure to the CP3? "Supply"
3: What does your rail pressure read?
4: Are there any codes?
5: Last fuel filter change?
6: Any smoke at start up or shut down?
I know you may not have some of these guages but it would be wise to have them!
Get back to me direct at: dangerous1965@cox.net
Andy

What ended up being the fix? I'm having similar issues with my 04.5.

While running Unplug your FCA Get scared and plug it back in....Recover time under 30 seconds?

Ok, have to ask, why am I getting scared?

:tttt: It will full pressure the rail and sound like it will blow up! don't worry it's a simple test!