Audi RS2 injectors, coils, pos, fuel and boost pressure values

[S2central.net]

Not sure i understand these fuel pressure readings... fuel pressure gauge should be in FEED line to the fuel rail... the regulator keeps it at 4bar above manifold pressure and lets excess fuel back to the tank via return pipe.

At idle with 0.5bar VACUUM in manifold you should have 3.5bar fuel pressure.
At 1.5bar BOOST you should see 5.5bar fuel pressure

The wobbly boost guage isn't a big worry - either the spring is a bit too stiff for the ECU programming or vice versa... WGFV duty is being adapted by ECU to keep boost on target - quite a coarse thing.

[Audi-Porsche Avant RS2]

Hello, my problem is that I don't know if I must connect the fuel pressure gauge between the in fuel pipe that come from to the fuel pump and filter and the in pipe that go in the injectors rail or between the return pipe that come from to the injectors rail and the return pipe that lets excess fuel back to the tank.
Thanks a lot!

Bye

Alessio

[S2central.net]

Guage should T'd into the FEED pipe.

The FPR is at the end of the fuel rail so that nominal 4bar pressure is evenly applied across all injectors. The pipe you see attached to the FPR is the return pipe... Fuel flows IN from front of engine / fuel rail.

[Audi-Porsche Avant RS2]

Ok, but for feed pipe what you mean? I know inlet pipe that come from the fuel pump and fuel filter and the return pipe.
Thanks a lot!

Alessio

[AndyP]

FEED=Inlet

[Audi-Porsche Avant RS2]

Ok, so on the pipe that come from the fuel pump and fuel filter?
For the pressure test is normal that the system don't remain pressurized? Or if there aren't boost leak must remain pressurized? Thanks!

Alessio