Fuel Pressure Issues

[yellowsnake]

I recently bought an 01 Cobra with a P-1SC Procharger. It has the generic tune, 42lb injectors, stock pump, TR-6's gaped @ .035" This car had 2800 miles on it when I bought it. Its been setting in the garage for some time. After getting some miles on her. I've decided to have some fun.

He's my problem, after installing the fuel pressure/ boost gauge. I noticed that @ full boost, around 5500rpms or so, the fuel pressure would drop off to 30 psi or below. During normal driving, it stayed around 42psi.

After reading about fuel pumps, the pros & cons of different styles & makes, I decided to go with the 04-aviator pump. Now I have plenty of pressure across the board. 50psi & drops to 40psi during WOT.

But, now the car is sluggish, stutters on its way up to higher rpms & the power level has dropped off consider.

Any ideas??
Thanks

[yellowsnake]

Up Date:

I did a test today on the way back from work @ the suggestion of a good friend. I removed the vaccum line from the fuel pressure regulator.

It drove perfect! Power was back, it pulled hard. So, did I prove the fuel pressure regulator is bad.