Can't get fuel pressure to go down

[chad-s12-drift]

I have had a walbro and nismo sr fpr in my car fo a while with no problem. I just put in a z32 maf and rx7 460 injectors with Rs Enthalpy tune and the car has 80 psi fuel pressure. I took the rail and line back off and blew air threw them there are no clogs or kinks yet with the fpr all the way loose it still has 80 psi. I don't see how the different injectors would make the pressure jump like that the only thing controlling pressure is the fpr right?

[idahotuner]

yes the FPR is the only thing, are you setting fuel pressure with the vacuum line disconected from the fpr

[float_6969]

I think you have the fuel feed and returns lines switched. If you run fuel through the FPR backwards it "dead heads" the fuel pump. Fuel path should be:
Fuel Pump->Fuel Filter->Fuel Rail->Fuel Pressure Regulator->Return line to Tank

[chad-s12-drift]

As soon as I turn the key to acc. it goes to 80psi and stays there even when the engine is running and the fpr is all the way loose . Also the fuel lines weren't disconnected when the new injectors were first put in I wish that was the fix lol. I don't see why different injector would make it spike up like that. It shouldnt make the rail pressure change only the fpr should which was working fine unless it a coincidence that it happen to go bad right then.

[TheMAN]

like float said... if you hooked up the fuel lines wrong, it can do this

[float_6969]

If you're sure the lines weren't disconnected, then you either have an obstruction on the return line to the tank, or the FPR was damaged.