3vze fuel pressure issue

[GilbertG]

I’ve been pretty stumped on a fuel pressure issue.
Gets 32 psi at idle and drops when I give it throttle. jumps up to 40 psi if I remove the regulator vacuum line or run the fuel pump through the diagnostic port.
Pressure doesn’t increase if I pinch the return line.
Getting 9v at the fuel pump but doesn’t drop with throttle , pulled the efi fuse and it was melted.

I’ve replaced the tps, fuel regulator, fuel pump (twice), fuel filter and the efi fuse.
Any help is appreciated

 

[84Prerunner]

Your pump can’t supply enough volume to keep up with crude in RPM. 9v is pretty low, can you rig up a jumper to supply a full 12+ v? Betting that helps a lot.