Weird widget under gas tank 2001 Cali

[Dnaj]

Got this new to me, 2001 California EV which had a slight fuel leak when running. Found this widget under the fuel tank in the return line. It was loose and the small hose fitting was also disconnected. What is it? My older California has a straight return line. Also, where  does the hose connect. I found a disconnected vacuum type hose under there but both ends are disconnected. Where might they connect. Thanks. 

[rocker59]

The nipple should remain open to air.

Not sure about the vacuum lines.  Could be left over from carbon canister removal, or could go to the tank vent outlets under the fuel tank

[Dnaj]

Thank you. What is it? If it's loose or leaking, could it cause a low idle occasional sputter or stall?

[bmc5733946]

That is the fuel pressure regulator, could cause running problems anytime.  Small hose to atmosphere.

Brian

[oldbike54]

That is the fuel pressure regulator, could cause running problems anytime.  Small hose to atmosphere.

Brian

 Hmm , always thought it was a flamilator exchanger valve 

 Think now that was wrong and it is fuel pressure regulator 

  Dusty

[Kiwi_Roy]

An early FI document showed the nipple connected to manifold vacuum, I suspect it was supposed to do something to the mixture but the ECU takes care of that, my EV has the regulator mounted on the frame with just a line going back to tank, same idea though.
The regulator sets the pressure at 45psi and the nipple should be open to atmosphere.

[twhitaker]

On my Centauro and LeMans the regulator is mounted where the second fuel tap would have been.

[oldbike54]

An early FI document showed the nipple connected to manifold vacuum, I suspect it was supposed to do something to the mixture but the ECU takes care of that, my EV has the regulator mounted on the frame with just a line going back to tank, same idea though.
The regulator sets the pressure at 45psi and the nipple should be open to atmosphere.

 Don't think it controlled mixture , the vacuum was to control the diaphragm . More vacuum , more
fuel that could pass through the regulator . At least that is the way I understand it 

  Dusty

 

[JoeW]

The vacuum diaphragm controls fuel pressure. With vacuum applied, it drops the fuel pressure about 5 psi. In automotive applications, manifold vacuum is applied to the regulator, under acceleration when intake manifold vacuum drops, fuel pressure is bumped up to aid in smooth acceleration. The ECMs on those vehicle are programmed for this, your bike is not. Just let it breath.

[Zoom Zoom]

What Rocker 59 told you is correct, including the probable emissions lines. 

Having an '01 EV from new, presently another one, and under the tank of a few others. There is nothing connected to that nipple.

John Henry