Small Block & Big Block Chevy Specific - fuel pressure problems

my fuel pressure on my camaro is between 27 to 30 psi at idle. I think its supposed to be between 41 to 47 psi. i checked my injectors they arent leaking, i checked my fuel filter and it seems to be fine. I also started it nd disconnected the regulator vacuum hose to simulate WOT and it jumps up like 10 psi then drops back to the low pressure at idle. I am planning on checking the pump next to see if maybe the strainer is bad or my pump is bad. Any help is appreciated. Thanks

I would change the fuel pump. if its an aftermarket pump go back to stock. I have put in 4 pumps in the past 6 months all have been walbro. I went back to stock. Also check the rubber or plastic lines on the fuel pump to make sure they are not split. If they are split replace them with a fuel injection hose for each one. hopefully this will help. Make sure to check the fuel pump relay when you change the pump out.