2001 Mustang Gt Fuel Problems

[Nathanil martin]

ive put new regulators fuel pump and new tank and fuel rail pressure sensors. Read the live streams fuel pressure drops at 4,000 rpm to 12 psi. I've got stage 4 comp cams pull vacumm of 20 and tap the throttle and it drops to 0 I'm wondering what's messing up my fuel pressure sensor on the rail

 

[wmburns]

Just wondering. Is the FRPS intake vacuum reference line connected and leak free? Is there any evidence of raw gas in the vacuum line?