I need some help here!! I've got a pretty stout 383 sbc in an 80 vette that I restored. I think the problem that I'm having is in my fuel system. I have a holley black (7psi) electronic fuel pump at the tank pushing the fuel through an aeromotive regulator to a holley 770 street avenger. The pressure guage will read 7.5 psi, and slowly drop to around 2. If I open the fuel line (post regulator) the pump seems to push air out of the line and then it will run great for a little while then start falling on it's face again with any rmp more than idle. Crazy thing is it runs great no matter what the guage reads when the car is sitting. It's when I drive it that it falls on its face. Any ideas?????  

Disreguard last... I have a holley Red, the smaller of the fuel pumps.  

the reason your car runs good while sitting is because 2psi is enough fuel supply for the car to idle, it's amazing how little fuel you need at idle. When you go to accelerate it falls on it's face cause 2 psi is not enough. All you gotta do is find out why the fuel presure is droping. I would recomend verying power and ground to the fuel pump with a voltmeter. However, if your problem was a power or ground issue It wouldn't cause the air in the line. Which leads me to belive there is probably a bad conection in the fuel line somewhere causing the system to draw in air. It might be inside the fuel tank or a bad sending unit. verify all your fuel line conections, pull out the sending unit, if no problems found there it might be a bad pump. I would only condem the pump after ruling out other issues. I am assuming the pump is mounted outside the tank. The likely hood of problems changes if the pump is mounted in the tank. I hope my insight is helpfull.