SOLVED hopefully. Fuel system not working.. wierd problem

[d-shiznit]

Wierd problem with my fuel system - when I try to adjust the pressure - anything above 20psi and the pressure regulator starts oscillating - pressure fluctuates between 20 - 60 psi on the gauge and the fuel lines can be heard rattling.

Anything <= 20psi is fine.

Fuel setup:
Surge tank
8-9mm feed and return lines
Bosch 044 external pump - capable of up to 72.5psi apparantly
Standard gen2 3sgte fuel rail
Fuel fed to both ends of rail - return in middle as in pic
Sard rising rate feul pressure regulator - adjustable up to 100psi apparantly

Any ideas anyone? I'm lost

[Cuzzo]

Can you please identify each inlet/oulet of the surge?

[d-shiznit]

Can you please identify each inlet/oulet of the surge?

See attached

[Duk]

Try putting the lifter pump line on the bottom feed. It's a guess, but the potential foaming effect from the fuel falling that far could be causing the main pump to be drawing in airated fuel that can cause cavitation and fuel line hammering.

[Cuzzo]

So you have two feeds from the surge to the motor?

[d-shiznit]

So you have two feeds from the surge to the motor?

No...
One feed from the surge to motor

[Cuzzo]

No...
One feed from the surge to motor

Sorry misread, got it!

[CrUZida]

Is the FPR hooked up correctly (I assume it is, just random question).

Have you checked the voltage at the pump at different pressures?

[d-shiznit]

Is the FPR hooked up correctly (I assume it is, just random question).

Have you checked the voltage at the pump at different pressures?

OHMYGOD I'm an idiot.

The instructions were japanese so I threw them out.
After searching around I realise that yes - I hooked the lines up the wrong way
Hope it hasn't damaged it.

Should be return into the side, outlet at bottom....
I stupidly assumed the other way around.

Thankyou for asking the obvious question CrUZida.