Does anyone know what the expected result should be when disconnecting the vacuum line to the fuel pressure regulator?

At idle, with a hot engine, the oxygen sensors did not change at all. (Mind you, I am running rich, sensors only fluctuate between 0.15 and 1.25 while driving, at idle they wander around the 0.25 range.)

Should the oxygen sensors report a change? Maybe when I'm driving? I haven't driven with the vacuum line plugged.

No error codes, and no squirting gas from the original regulator. Just trying to figure out why my O2 sensors don't wander to the upper limits of the sensor range (4.50)

Thanks.

 

is that volts?

 

Yes, volts. Remember, I'm working with these fancy Titania sensors

 

I was told that the vac line from the fuel pressure regulator is meant to somehow adjust the regulated fuel pressure according to the manifold vacuum. I am guessing here, but I would expect that when the manifold vacuum falls as the throttles open, the regulated fuel pressure rises slightly. Grant Francis has told us that on his cars he gets rid of the RH regulator completely, and removes the vac line from the B bank regulator (and even has changed the LH regulator for an aftermarket one located off the engine).

At least I think this is what he said.
Greg

 

for myself,i did not like the way jag designed the fuel rails and two regulators.

pix shows a much simpler system, custom rail aluminum and adjustable regulator, i use custom larger injectors, but can control pressure for fine tuning.

it works the best with an aftermarket ECU.

at idle vac hose on vs off changes F/pressure about 5-10psi. i use an A/F ratio gage for tuning, along with seat of pants driveability.

 

I have the AJ16, so only one regulator.

I'm wondering why I can't plumb an inline gauge here?