Well guys and gals I've been incredibly busy recently. 

Well here is the short story. I recently replaced my pressure side fuel line from the Airdog to the VP44 all is well and no issues with that project. So the pressure starts to fall off only on wide open throttle and is getting worse over time. Any time I go wide open the lift pressure falls from 16 PSI to 13 PSI I've even seen it as low as 12 PSI.

This has been going on since early this month. I have replaced fuel and water separator filters twice and it makes no difference. Also it seems the electrical is having issues. I have rebuilt a section of the harness that attaches the relay into the circuit. All points that were added were soldered in and I don't see any wild voltage drops across the system. 

I am beginning to think the pump motor can't keep up due to worn out brushes. 

If anybody knows anything else that could let the pressure drop and only at wide open throttle let me know?

Just now, CSM said:

Mostly, but it also happens once in a while while I am driving around.  Starts out at 10psi and then slowwwwwlllly gets up to 14 with occasional drops down to 12, then it stabilizes for the rest of the drive at 15.  I need to do some testing on it once the draw straw is in.  I want to compare cavitation sounds vs load vs pressure etc.  

Sounds like it could be an air issue. Check your fittings first. After that look at the return/relief spring and possibly replace it with a new one.