regulator fuel leak

[sculler2x]

Saturday, I put my gas tank back on and put some fuel in it.  I primed the system by toggling the kill switch, this drives all the air out of the lines.  This resulted in fuel spraying from somewhere.  I removed the regulator and took it apart.  I found 2 possible sources.

 

1 The cast housing had a ragged parting line on the hose barb.  I filed and sanded it smooth.

 

2 The O-rings inside were unlubricated.  I lubed them with fuel proof grease and put it back together.

 

This solved the leaking problem.  I discovered while I had the regulator apart that there was no adjustment possible.  I had often wondered what the small stalk sticking out of the side was for.  I suspect that you could connect it to the manifold on a supercharged engine to deliver higher injector pressure when there is boost.

[swooshdave]

 

The stalk at the bottom?

 

I suppose you are right, not planning on putting a supercharger on the ol' V11, are we? 

[docc]

The "stalk" is open to atmosphere.

[GuzziMoto]

The "stalk" is open to atmosphere.

It does that so it can use the atmospheric pressure as a reference for the fuel pressure. Typically pressures are measured relative to something else, like the air pressure in your tires is relative to the air pressure outside your tires. Your tire pressure gauge is actually measuring the air pressure inside your tires compared to the air pressure outside your tires.

As mentioned, that nipple is providing the reference for the fuel pressure. If you connected it to, say, the intake tract using the same port you use for balancing your throttle bodies it would mean the fuel pressure would be maintained at the set pressure relative to the pressure (or lack there of) in the intake tract. I think some have tried this thinking it would run better, but it seems that it does not. Perhaps if someone put more effort into it, but I can't imaging it is worth it.

Just leave it open to atmo.

[footgoose]

well, I've always wondered about that thing. thanks for the explanation.

[Kiwi_Roy]

On the early systems it was connected to the manifold as shown,

 

http://www.dpguzzi.com/efiman.pdf

 

 

The Efiman document is worth it's weight in gold when trying to understand the fuel injection.

Although Its written for an earlier system 95% of it is still applicable.