Today's Message Index:
----------------------
1. 04:20 AM - Re: Fuel Pressure Fixed (Ron Schreck)
2. 04:29 AM - Re: Fuel Pressure Fixed (Steve Glasgow)
3. 05:06 AM - Re: Fuel Pressure Fixed (Bill Boyd)
4. 05:28 AM - Re: Fuel Pressure Fixed (Steve Glasgow)
5. 05:44 AM - Re: Fuel Pressure Fixed (Bill Boyd)
6. 05:58 AM - Re: Fuel Pressure Fixed (James Clark)
7. 06:31 AM - Re: Fuel Pressure Fixed (Bill Boyd)
8. 07:25 AM - bubbles and pressure was : Fuel Pressure Fixed (Ed Anderson)
9. 10:24 AM - Re: bubbles and pressure was : Fuel Pressure Fixed (Bill Boyd)
10. 10:57 AM - Re: bubbles and pressure was : Fuel Pressure Fixed (Steve Glasgow)
11. 06:22 PM - Re: bubbles and pressure was : Fuel Pressure Fixed (Bill Boyd)
12. 06:28 PM - Re: bubbles and pressure was : Fuel Pressure Fixed (Bill Boyd)
13. 07:48 PM - Re: bubbles and pressure was : Fuel Pressure Fixed (Ed Anderson)
Message 1
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| Subject: | Fuel Pressure Fixed |
Steve,
Glad to hear you are back in the air. Actually, your problem and
solution makes perfect sense to me (Monday morning quarterbacking,
however). If your fuel and oil pressure sensors are mounted high on the
firewall, it only makes sense that any air trapped in the lines will
never bleed out (down hill) without some help. True, the trapped air
may transfer some measure of pressure, but being much more compressible
than a liquid it would certainly be a false reading. I think your
solution merits a mention on the RV list and perhaps a suggestion that
these sensors be mounted low on the firewall to avoid the problem
altogether. Nice work, Cappy!
Smokey
-----Original Message-----
From: owner-rvsoutheast-list-server@matronics.com
[mailto:owner-rvsoutheast-list-server@matronics.com] On Behalf Of Steve
Glasgow
Sent: Saturday, January 27, 2007 5:13 PM
Subject: RVSouthEast-List: Fuel Pressure Fixed
--> <willfly@carolina.rr.com>
Turns out there was apparently air in the line to the sender. Probably
from
lines being open on annual.
I flew before doing the procedure below and the fuel pressure was all
over
the place. From 4 to 9.5 psi.
Anyway here is what to do to get the air out. Disconnect wires from
fuel
sender. Loosen sender so it can be moved by hand. Keep sender hand
tight
and turn on electric pump. Now loosen sender till fuel comes out around
the
pipe fitting. Then tighten to stop the fuel from leaking. Turn off
electric pump, secure sender and hook up wires. Done. From now on I
will
do this procedure whenever a fuel line is opened.
I flew before doing this and the fuel pressure was all over the place.
>From
4 to 9.5 psi.
Cappy
--
1/26/2007 11:11 AM
--
1/27/2007 5:02 PM
Message 2
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| Subject: | Re: Fuel Pressure Fixed |
Thanks for the Kudos Smokey! As you know I have been dealing with Low
or High fuel pressure since the beginning so I'm whiting till the jury
is in. I have ordered a direct reading pressure gauge that should be
here Wednesday. Then I can find out what the "real fuel pressure" is.
Cappy
----- Original Message -----
From: Ron Schreck
To: rvsoutheast-list@matronics.com
Sent: Sunday, January 28, 2007 7:17 AM
Subject: RE: RVSouthEast-List: Fuel Pressure Fixed
<ronschreck@alltel.net>
Steve,
Glad to hear you are back in the air. Actually, your problem and
solution makes perfect sense to me (Monday morning quarterbacking,
however). If your fuel and oil pressure sensors are mounted high on
the
firewall, it only makes sense that any air trapped in the lines will
never bleed out (down hill) without some help. True, the trapped air
may transfer some measure of pressure, but being much more
compressible
than a liquid it would certainly be a false reading. I think your
solution merits a mention on the RV list and perhaps a suggestion that
these sensors be mounted low on the firewall to avoid the problem
altogether. Nice work, Cappy!
Smokey
-----Original Message-----
From: owner-rvsoutheast-list-server@matronics.com
[mailto:owner-rvsoutheast-list-server@matronics.com] On Behalf Of
Steve
Glasgow
Sent: Saturday, January 27, 2007 5:13 PM
To: SERV
Subject: RVSouthEast-List: Fuel Pressure Fixed
--> <willfly@carolina.rr.com>
Turns out there was apparently air in the line to the sender.
Probably
from
lines being open on annual.
I flew before doing the procedure below and the fuel pressure was all
over
the place. From 4 to 9.5 psi.
Anyway here is what to do to get the air out. Disconnect wires from
fuel
sender. Loosen sender so it can be moved by hand. Keep sender hand
tight
and turn on electric pump. Now loosen sender till fuel comes out
around
the
pipe fitting. Then tighten to stop the fuel from leaking. Turn off
electric pump, secure sender and hook up wires. Done. From now on I
will
do this procedure whenever a fuel line is opened.
I flew before doing this and the fuel pressure was all over the place.
>From
4 to 9.5 psi.
Cappy
--
1/26/2007 11:11 AM
--
1/27/2007 5:02 PM
Message 3
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| Subject: | Re: Fuel Pressure Fixed |
Smokey,
I think the trapped air compresses until it reaches equilib. and then
transmits all the pressure on down the line... in doing so it will
tend to dampen any pulses (soften the water-hammer effect,
what-have-you) but I think all the pressure will show up at the
transducer. Enlighten me if I'm overlooking the obvious.
It sounds like Cappy might have fixed his gauge but broken some law of
physics. Typical Cappy maneuver if you ask me. Today I shall have to
see if he messed up Bernouli and Newton's, by seeing if my wing still
generates enough lift to fly :-)
Cappy, I'd appreciate it if you wouldn't break or damage physical laws
that the rest of us use every day, just to get your gauges reading
correctly; that's very selfish and won't be tolerated.
-Stormy
On 1/28/07, Ron Schreck <ronschreck@alltel.net> wrote:
>
> Steve,
>
> Glad to hear you are back in the air. Actually, your problem and
> solution makes perfect sense to me (Monday morning quarterbacking,
> however). If your fuel and oil pressure sensors are mounted high on the
> firewall, it only makes sense that any air trapped in the lines will
> never bleed out (down hill) without some help. True, the trapped air
> may transfer some measure of pressure, but being much more compressible
> than a liquid it would certainly be a false reading. I think your
> solution merits a mention on the RV list and perhaps a suggestion that
> these sensors be mounted low on the firewall to avoid the problem
> altogether. Nice work, Cappy!
>
> Smokey
>
> -----Original Message-----
> From: owner-rvsoutheast-list-server@matronics.com
> [mailto:owner-rvsoutheast-list-server@matronics.com] On Behalf Of Steve
> Glasgow
> Sent: Saturday, January 27, 2007 5:13 PM
> To: SERV
> Subject: RVSouthEast-List: Fuel Pressure Fixed
>
>
> --> <willfly@carolina.rr.com>
>
> Turns out there was apparently air in the line to the sender. Probably
> from
> lines being open on annual.
>
> I flew before doing the procedure below and the fuel pressure was all
> over
> the place. From 4 to 9.5 psi.
>
> Anyway here is what to do to get the air out. Disconnect wires from
> fuel
> sender. Loosen sender so it can be moved by hand. Keep sender hand
> tight
> and turn on electric pump. Now loosen sender till fuel comes out around
> the
> pipe fitting. Then tighten to stop the fuel from leaking. Turn off
> electric pump, secure sender and hook up wires. Done. From now on I
> will
> do this procedure whenever a fuel line is opened.
>
> I flew before doing this and the fuel pressure was all over the place.
> >From
> 4 to 9.5 psi.
>
> Cappy
>
>
> --
> 1/26/2007 11:11 AM
>
>
> --
> 1/27/2007 5:02 PM
>
>
Message 4
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| Subject: | Re: Fuel Pressure Fixed |
What about compressibility of a gas verses a liquid. Water pipes have
air trapped in them all the time to prevent hammer effect. The pressure
sender is up the line not down the line. Pressure is correct at the
engine, just not the pressure sender which is way above the carburetor.
You may be correct if the sender is plumbed at the carburetor but mine
isn't. All I know is it worked. No more oscillating fuel pressure.
Stormy, are you giving us bad coordinates again?
Love Cappy
----- Original Message -----
From: Bill Boyd
To: rvsoutheast-list@matronics.com
Sent: Sunday, January 28, 2007 8:05 AM
Subject: Re: RVSouthEast-List: Fuel Pressure Fixed
<sportav8r@gmail.com>
Smokey,
I think the trapped air compresses until it reaches equilib. and then
transmits all the pressure on down the line... in doing so it will
tend to dampen any pulses (soften the water-hammer effect,
what-have-you) but I think all the pressure will show up at the
transducer. Enlighten me if I'm overlooking the obvious.
It sounds like Cappy might have fixed his gauge but broken some law of
physics. Typical Cappy maneuver if you ask me. Today I shall have to
see if he messed up Bernouli and Newton's, by seeing if my wing still
generates enough lift to fly :-)
Cappy, I'd appreciate it if you wouldn't break or damage physical laws
that the rest of us use every day, just to get your gauges reading
correctly; that's very selfish and won't be tolerated.
-Stormy
On 1/28/07, Ron Schreck <ronschreck@alltel.net> wrote:
<ronschreck@alltel.net>
>
> Steve,
>
> Glad to hear you are back in the air. Actually, your problem and
> solution makes perfect sense to me (Monday morning quarterbacking,
> however). If your fuel and oil pressure sensors are mounted high on
the
> firewall, it only makes sense that any air trapped in the lines will
> never bleed out (down hill) without some help. True, the trapped
air
> may transfer some measure of pressure, but being much more
compressible
> than a liquid it would certainly be a false reading. I think your
> solution merits a mention on the RV list and perhaps a suggestion
that
> these sensors be mounted low on the firewall to avoid the problem
> altogether. Nice work, Cappy!
>
> Smokey
>
> -----Original Message-----
> From: owner-rvsoutheast-list-server@matronics.com
> [mailto:owner-rvsoutheast-list-server@matronics.com] On Behalf Of
Steve
> Glasgow
> Sent: Saturday, January 27, 2007 5:13 PM
> To: SERV
> Subject: RVSouthEast-List: Fuel Pressure Fixed
>
>
> --> <willfly@carolina.rr.com>
>
> Turns out there was apparently air in the line to the sender.
Probably
> from
> lines being open on annual.
>
> I flew before doing the procedure below and the fuel pressure was
all
> over
> the place. From 4 to 9.5 psi.
>
> Anyway here is what to do to get the air out. Disconnect wires from
> fuel
> sender. Loosen sender so it can be moved by hand. Keep sender hand
> tight
> and turn on electric pump. Now loosen sender till fuel comes out
around
> the
> pipe fitting. Then tighten to stop the fuel from leaking. Turn off
> electric pump, secure sender and hook up wires. Done. From now on
I
> will
> do this procedure whenever a fuel line is opened.
>
> I flew before doing this and the fuel pressure was all over the
place.
> >From
> 4 to 9.5 psi.
>
> Cappy
>
>
>
>
>
>
> --
> 1/26/2007 11:11 AM
>
>
> --
> 1/27/2007 5:02 PM
>
>
>
>
>
>
>
Message 5
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|
| Subject: | Re: Fuel Pressure Fixed |
Yeah, I've been known to lose my position fix on the internet before...
I'm wrestling with this and want to understand it. You raise one
(calibration) point below: the pressure you read will be less than
carb pressure by the height of the fluid column betwee the carb and
the transducer. Not sure how many inches of gasoline column equal one
p.s.i., but it varies with gasoline versus air because of the
differing densities. Same reason a barometer made with mercury is
only a few feet tall versus one with water at around 32 feet tall!
The way I look at it, the pressure at my air tool is at the same value
as at the compressor regulator (until I squeeze the trigger and air
flow in the line causes a "voltage drop" - I'm talking about static
pressure, such as we read in a fuel pressure line that dead-ends into
a transducer). To me this demonstrates that air sends its pressure
down the hose just like any other fluid, otherwise my pneumatic tools
would not work.
I still believe that when your fuel system pressurizes, everything in
the system, even trapped air, comes up to the same pressure and should
read as such on any transducer. If I'm mistaken, let me know;
meanwhile my air tools still work just dandy on this exact principle.
But as you say, I've been wrong before.
I only belabor the point b/c I'm not convinced that this could have
fixed the problem and you might need to keep investigating.
-Stormy
On 1/28/07, Steve Glasgow <willfly@carolina.rr.com> wrote:
>
>
> What about compressibility of a gas verses a liquid. Water pipes have air
> trapped in them all the time to prevent hammer effect. The pressure sender
> is up the line not down the line. Pressure is correct at the engine, just
> not the pressure sender which is way above the carburetor. You may be
> correct if the sender is plumbed at the carburetor but mine isn't. All I
> know is it worked. No more oscillating fuel pressure.
>
> Stormy, are you giving us bad coordinates again?
>
> Love Cappy
>
> ----- Original Message -----
> From: Bill Boyd
> To: rvsoutheast-list@matronics.com
> Sent: Sunday, January 28, 2007 8:05 AM
> Subject: Re: RVSouthEast-List: Fuel Pressure Fixed
>
>
> Smokey,
>
> I think the trapped air compresses until it reaches equilib. and then
> transmits all the pressure on down the line... in doing so it will
> tend to dampen any pulses (soften the water-hammer effect,
> what-have-you) but I think all the pressure will show up at the
> transducer. Enlighten me if I'm overlooking the obvious.
>
> It sounds like Cappy might have fixed his gauge but broken some law of
> physics. Typical Cappy maneuver if you ask me. Today I shall have to
> see if he messed up Bernouli and Newton's, by seeing if my wing still
> generates enough lift to fly :-)
>
> Cappy, I'd appreciate it if you wouldn't break or damage physical laws
> that the rest of us use every day, just to get your gauges reading
> correctly; that's very selfish and won't be tolerated.
>
> -Stormy
>
> On 1/28/07, Ron Schreck <ronschreck@alltel.net> wrote:
> <ronschreck@alltel.net>
> >
> > Steve,
> >
> > Glad to hear you are back in the air. Actually, your problem and
> > solution makes perfect sense to me (Monday morning quarterbacking,
> > however). If your fuel and oil pressure sensors are mounted high on the
> > firewall, it only makes sense that any air trapped in the lines will
> > never bleed out (down hill) without some help. True, the trapped air
> > may transfer some measure of pressure, but being much more compressible
> > than a liquid it would certainly be a false reading. I think your
> > solution merits a mention on the RV list and perhaps a suggestion that
> > these sensors be mounted low on the firewall to avoid the problem
> > altogether. Nice work, Cappy!
> >
> > Smokey
> >
> > -----Original Message-----
> > From: owner-rvsoutheast-list-server@matronics.com
> > [mailto:owner-rvsoutheast-list-server@matronics.com] On
> Behalf Of Steve
> > Glasgow
> > Sent: Saturday, January 27, 2007 5:13 PM
> > To: SERV
> > Subject: RVSouthEast-List: Fuel Pressure Fixed
> >
> >
> > --> <willfly@carolina.rr.com>
> >
> > Turns out there was apparently air in the line to the sender. Probably
> > from
> > lines being open on annual.
> >
> > I flew before doing the procedure below and the fuel pressure was all
> > over
> > the place. From 4 to 9.5 psi.
> >
> > Anyway here is what to do to get the air out. Disconnect wires from
> > fuel
> > sender. Loosen sender so it can be moved by hand. Keep sender hand
> > tight
> > and turn on electric pump. Now loosen sender till fuel comes out around
> > the
> > pipe fitting. Then tighten to stop the fuel from leaking. Turn off
> > electric pump, secure sender and hook up wires. Done. From now on I
> > will
> > do this procedure whenever a fuel line is opened.
> >
> > I flew before doing this and the fuel pressure was all over the place.
> > >From
> > 4 to 9.5 psi.
> >
> > Cappy
> >
> >
> >
> >
> >
> >
> > --
> > 1/26/2007 11:11 AM
> >
> >
> > --
> > 1/27/2007 5:02 p; Features Subscriptions
> href="http://www.matronics.com/Navigator?RVSouthEast-List">http://www.mp;
> available via
> href="http://forums.matronics.com">http://forums.matronics.com
>
>
Message 6
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| Subject: | Re: Fuel Pressure Fixed |
Consider this: Removing the "air" may have been the mechanism that removed
some other "trapped particle" that might have been affecting the transducer.
James
On 1/28/07, Bill Boyd <sportav8r@gmail.com> wrote:
>
>
> Yeah, I've been known to lose my position fix on the internet before...
>
> I'm wrestling with this and want to understand it. You raise one
> (calibration) point below: the pressure you read will be less than
> carb pressure by the height of the fluid column betwee the carb and
> the transducer. Not sure how many inches of gasoline column equal one
> p.s.i., but it varies with gasoline versus air because of the
> differing densities. Same reason a barometer made with mercury is
> only a few feet tall versus one with water at around 32 feet tall!
>
> The way I look at it, the pressure at my air tool is at the same value
> as at the compressor regulator (until I squeeze the trigger and air
> flow in the line causes a "voltage drop" - I'm talking about static
> pressure, such as we read in a fuel pressure line that dead-ends into
> a transducer). To me this demonstrates that air sends its pressure
> down the hose just like any other fluid, otherwise my pneumatic tools
> would not work.
>
> I still believe that when your fuel system pressurizes, everything in
> the system, even trapped air, comes up to the same pressure and should
> read as such on any transducer. If I'm mistaken, let me know;
> meanwhile my air tools still work just dandy on this exact principle.
> But as you say, I've been wrong before.
>
> I only belabor the point b/c I'm not convinced that this could have
> fixed the problem and you might need to keep investigating.
>
> -Stormy
>
> On 1/28/07, Steve Glasgow <willfly@carolina.rr.com> wrote:
> >
> >
> > What about compressibility of a gas verses a liquid. Water pipes have
> air
> > trapped in them all the time to prevent hammer effect. The pressure
> sender
> > is up the line not down the line. Pressure is correct at the engine,
> just
> > not the pressure sender which is way above the carburetor. You may be
> > correct if the sender is plumbed at the carburetor but mine
> isn't. All I
> > know is it worked. No more oscillating fuel pressure.
> >
> > Stormy, are you giving us bad coordinates again?
> >
> > Love Cappy
> >
> > ----- Original Message -----
> > From: Bill Boyd
> > To: rvsoutheast-list@matronics.com
> > Sent: Sunday, January 28, 2007 8:05 AM
> > Subject: Re: RVSouthEast-List: Fuel Pressure Fixed
> >
> >
> >
> > Smokey,
> >
> > I think the trapped air compresses until it reaches equilib. and then
> > transmits all the pressure on down the line... in doing so it will
> > tend to dampen any pulses (soften the water-hammer effect,
> > what-have-you) but I think all the pressure will show up at the
> > transducer. Enlighten me if I'm overlooking the obvious.
> >
> > It sounds like Cappy might have fixed his gauge but broken some law of
> > physics. Typical Cappy maneuver if you ask me. Today I shall have to
> > see if he messed up Bernouli and Newton's, by seeing if my wing still
> > generates enough lift to fly :-)
> >
> > Cappy, I'd appreciate it if you wouldn't break or damage physical laws
> > that the rest of us use every day, just to get your gauges reading
> > correctly; that's very selfish and won't be tolerated.
> >
> > -Stormy
> >
> > On 1/28/07, Ron Schreck <ronschreck@alltel.net> wrote:
> > <ronschreck@alltel.net>
> > >
> > > Steve,
> > >
> > > Glad to hear you are back in the air. Actually, your problem and
> > > solution makes perfect sense to me (Monday morning quarterbacking,
> > > however). If your fuel and oil pressure sensors are mounted high on
> the
> > > firewall, it only makes sense that any air trapped in the lines will
> > > never bleed out (down hill) without some help. True, the trapped air
> > > may transfer some measure of pressure, but being much more
> compressible
> > > than a liquid it would certainly be a false reading. I think your
> > > solution merits a mention on the RV list and perhaps a suggestion that
> > > these sensors be mounted low on the firewall to avoid the problem
> > > altogether. Nice work, Cappy!
> > >
> > > Smokey
> > >
> > > -----Original Message-----
> > > From: owner-rvsoutheast-list-server@matronics.com
> > > [mailto:owner-rvsoutheast-list-server@matronics.com] On
> > Behalf Of Steve
> > > Glasgow
> > > Sent: Saturday, January 27, 2007 5:13 PM
> > > To: SERV
> > > Subject: RVSouthEast-List: Fuel Pressure Fixed
> > >
> > >
> > > --> <willfly@carolina.rr.com>
> > >
> > > Turns out there was apparently air in the line to the
> sender. Probably
> > > from
> > > lines being open on annual.
> > >
> > > I flew before doing the procedure below and the fuel pressure was all
> > > over
> > > the place. From 4 to 9.5 psi.
> > >
> > > Anyway here is what to do to get the air out. Disconnect wires from
> > > fuel
> > > sender. Loosen sender so it can be moved by hand. Keep sender hand
> > > tight
> > > and turn on electric pump. Now loosen sender till fuel comes out
> around
> > > the
> > > pipe fitting. Then tighten to stop the fuel from leaking. Turn off
> > > electric pump, secure sender and hook up wires. Done. From now on I
> > > will
> > > do this procedure whenever a fuel line is opened.
> > >
> > > I flew before doing this and the fuel pressure was all over the place.
> > > >From
> > > 4 to 9.5 psi.
> > >
> > > Cappy
> > >
> > >
> > >
> > >
> > >
> > >
> > > --
> > > 1/26/2007 11:11 AM
> > >
> > >
> > > --
> > > 1/27/2007 5:02 p; Features Subscriptions
> > href="http://www.matronics.com/Navigator?RVSouthEast-List">http://www.mp
> ;
> > available via
> > href="http://forums.matronics.com">http://forums.matronics.com
> >
> >
> >
> >
> >
> >
>
>
--
This is an alternate email. Please continue to email me at
james@nextupventures.com .
Message 7
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| Subject: | Re: Fuel Pressure Fixed |
One never knows.
Seems these transducers do have a troubled service history, though.
Swaping them out usually fixes whatever problem one is posting to the
list about :-) Steve's direct reading gauge will tell all when he
gets it hooked in.
-B
On 1/28/07, James Clark <jclarkmail@gmail.com> wrote:
> Consider this: Removing the "air" may have been the mechanism that removed
> some other "trapped particle" that might have been affecting the transducer.
>
> James
>
>
> On 1/28/07, Bill Boyd <sportav8r@gmail.com> wrote:
> >
> > Yeah, I've been known to lose my position fix on the internet before...
> >
> > I'm wrestling with this and want to understand it. You raise one
> > (calibration) point below: the pressure you read will be less than
> > carb pressure by the height of the fluid column betwee the carb and
> > the transducer. Not sure how many inches of gasoline column equal one
> > p.s.i., but it varies with gasoline versus air because of the
> > differing densities. Same reason a barometer made with mercury is
> > only a few feet tall versus one with water at around 32 feet tall!
> >
> > The way I look at it, the pressure at my air tool is at the same value
> > as at the compressor regulator (until I squeeze the trigger and air
> > flow in the line causes a "voltage drop" - I'm talking about static
> > pressure, such as we read in a fuel pressure line that dead-ends into
> > a transducer). To me this demonstrates that air sends its pressure
> > down the hose just like any other fluid, otherwise my pneumatic tools
> > would not work.
> >
> > I still believe that when your fuel system pressurizes, everything in
> > the system, even trapped air, comes up to the same pressure and should
> > read as such on any transducer. If I'm mistaken, let me know;
> > meanwhile my air tools still work just dandy on this exact principle.
> > But as you say, I've been wrong before.
> >
> > I only belabor the point b/c I'm not convinced that this could have
> > fixed the problem and you might need to keep investigating.
> >
> > -Stormy
> >
> > On 1/28/07, Steve Glasgow < willfly@carolina.rr.com> wrote:
> > >
> > >
> > > What about compressibility of a gas verses a liquid. Water pipes have
> air
> > > trapped in them all the time to prevent hammer effect. The pressure
> sender
> > > is up the line not down the line. Pressure is correct at the engine,
> just
> > > not the pressure sender which is way above the carburetor. You may be
> > > correct if the sender is plumbed at the carburetor but mine isn't.
> All I
> > > know is it worked. No more oscillating fuel pressure.
> > >
> > > Stormy, are you giving us bad coordinates again?
> > >
> > > Love Cappy
> > >
> > > ----- Original Message -----
> > > From: Bill Boyd
> > > To: rvsoutheast-list@matronics.com
> > > Sent: Sunday, January 28, 2007 8:05 AM
> > > Subject: Re: RVSouthEast-List: Fuel Pressure Fixed
> > >
> sportav8r@gmail.com>
> > >
> > > Smokey,
> > >
> > > I think the trapped air compresses until it reaches equilib. and then
> > > transmits all the pressure on down the line... in doing so it will
> > > tend to dampen any pulses (soften the water-hammer effect,
> > > what-have-you) but I think all the pressure will show up at the
> > > transducer. Enlighten me if I'm overlooking the obvious.
> > >
> > > It sounds like Cappy might have fixed his gauge but broken some law of
> > > physics. Typical Cappy maneuver if you ask me. Today I shall have to
> > > see if he messed up Bernouli and Newton's, by seeing if my wing still
> > > generates enough lift to fly :-)
> > >
> > > Cappy, I'd appreciate it if you wouldn't break or damage physical laws
> > > that the rest of us use every day, just to get your gauges reading
> > > correctly; that's very selfish and won't be tolerated.
> > >
> > > -Stormy
> > >
> > > On 1/28/07, Ron Schreck <ronschreck@alltel.net> wrote:
> > > <ronschreck@alltel.net>
> > > >
> > > > Steve,
> > > >
> > > > Glad to hear you are back in the air. Actually, your problem and
> > > > solution makes perfect sense to me (Monday morning quarterbacking,
> > > > however). If your fuel and oil pressure sensors are mounted high on
> the
> > > > firewall, it only makes sense that any air trapped in the lines will
> > > > never bleed out (down hill) without some help. True, the trapped air
> > > > may transfer some measure of pressure, but being much more
> compressible
> > > > than a liquid it would certainly be a false reading. I think your
> > > > solution merits a mention on the RV list and perhaps a suggestion that
> > > > these sensors be mounted low on the firewall to avoid the problem
> > > > altogether. Nice work, Cappy!
> > > >
> > > > Smokey
> > > >
> > > > -----Original Message-----
> > > > From: owner-rvsoutheast-list-server@matronics.com
> > > > [mailto:owner-rvsoutheast-list-server@matronics.com ]
> On
> > > Behalf Of Steve
> > > > Glasgow
> > > > Sent: Saturday, January 27, 2007 5:13 PM
> > > > To: SERV
> > > > Subject: RVSouthEast-List: Fuel Pressure Fixed
> > > >
> > > >
> > > > --> <willfly@carolina.rr.com>
> > > >
> > > > Turns out there was apparently air in the line to the sender.
> Probably
> > > > from
> > > > lines being open on annual.
> > > >
> > > > I flew before doing the procedure below and the fuel pressure was all
> > > > over
> > > > the place. From 4 to 9.5 psi.
> > > >
> > > > Anyway here is what to do to get the air out. Disconnect wires from
> > > > fuel
> > > > sender. Loosen sender so it can be moved by hand. Keep sender hand
> > > > tight
> > > > and turn on electric pump. Now loosen sender till fuel comes out
> around
> > > > the
> > > > pipe fitting. Then tighten to stop the fuel from leaking. Turn off
> > > > electric pump, secure sender and hook up wires. Done. From now on I
> > > > will
> > > > do this procedure whenever a fuel line is opened.
> > > >
> > > > I flew before doing this and the fuel pressure was all over the place.
> > > > >From
> > > > 4 to 9.5 psi.
> > > >
> > > > Cappy
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > > --
> > > > 1/26/2007 11:11 AM
> > > >
> > > >
> > > > --
> > > > 1/27/2007 5:02 p; Features Subscriptions
> > > href="
> http://www.matronics.com/Navigator?RVSouthEast-List">http://www.mp;
> > > available via
> > > href="http://forums.matronics.com
> >
> >
> >
>
>
> --
> This is an alternate email. Please continue to email me at
> james@nextupventures.com .
>
>
Message 8
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| Subject: | Fuel Pressure Fixed |
I think you are correct, Cappy. There are several states of gas that
can exist in a liquid, some which cause worst effects than others, but
in any case, they all appear to affect pressure measurements in a line
to various degrees. Although, the attached refers to air in a hydraulic
system the effects are the same in a pressurized fuel line. Note that
bubbles can cause changes in head pressure as well as erroneous
measurements and response delays.
Ed
----- Original Message -----
From: Steve Glasgow
To: rvsoutheast-list@matronics.com
Sent: Sunday, January 28, 2007 8:27 AM
Subject: Re: RVSouthEast-List: Fuel Pressure Fixed
What about compressibility of a gas verses a liquid. Water pipes have
air trapped in them all the time to prevent hammer effect. The pressure
sender is up the line not down the line. Pressure is correct at the
engine, just not the pressure sender which is way above the carburetor.
You may be correct if the sender is plumbed at the carburetor but mine
isn't. All I know is it worked. No more oscillating fuel pressure.
Stormy, are you giving us bad coordinates again?
Love Cappy
----- Original Message -----
From: Bill Boyd
To: rvsoutheast-list@matronics.com
Sent: Sunday, January 28, 2007 8:05 AM
Subject: Re: RVSouthEast-List: Fuel Pressure Fixed
<sportav8r@gmail.com>
Smokey,
I think the trapped air compresses until it reaches equilib. and
then
transmits all the pressure on down the line... in doing so it will
tend to dampen any pulses (soften the water-hammer effect,
what-have-you) but I think all the pressure will show up at the
transducer. Enlighten me if I'm overlooking the obvious.
It sounds like Cappy might have fixed his gauge but broken some law
of
physics. Typical Cappy maneuver if you ask me. Today I shall have
to
see if he messed up Bernouli and Newton's, by seeing if my wing
still
generates enough lift to fly :-)
Cappy, I'd appreciate it if you wouldn't break or damage physical
laws
that the rest of us use every day, just to get your gauges reading
correctly; that's very selfish and won't be tolerated.
-Stormy
On 1/28/07, Ron Schreck <ronschreck@alltel.net> wrote:
<ronschreck@alltel.net>
>
> Steve,
>
> Glad to hear you are back in the air. Actually, your problem and
> solution makes perfect sense to me (Monday morning quarterbacking,
> however). If your fuel and oil pressure sensors are mounted high
on the
> firewall, it only makes sense that any air trapped in the lines
will
> never bleed out (down hill) without some help. True, the trapped
air
> may transfer some measure of pressure, but being much more
compressible
> than a liquid it would certainly be a false reading. I think your
> solution merits a mention on the RV list and perhaps a suggestion
that
> these sensors be mounted low on the firewall to avoid the problem
> altogether. Nice work, Cappy!
>
> Smokey
>
> -----Original Message-----
> From: owner-rvsoutheast-list-server@matronics.com
> [mailto:owner-rvsoutheast-list-server@matronics.com] On Behalf Of
Steve
> Glasgow
> Sent: Saturday, January 27, 2007 5:13 PM
> To: SERV
> Subject: RVSouthEast-List: Fuel Pressure Fixed
>
>
> --> <willfly@carolina.rr.com>
>
> Turns out there was apparently air in the line to the sender.
Probably
> from
> lines being open on annual.
>
> I flew before doing the procedure below and the fuel pressure was
all
> over
> the place. From 4 to 9.5 psi.
>
> Anyway here is what to do to get the air out. Disconnect wires
from
> fuel
> sender. Loosen sender so it can be moved by hand. Keep sender
hand
> tight
> and turn on electric pump. Now loosen sender till fuel comes out
around
> the
> pipe fitting. Then tighten to stop the fuel from leaking. Turn
off
> electric pump, secure sender and hook up wires. Done. From now
on I
> will
> do this procedure whenever a fuel line is opened.
>
> I flew before doing this and the fuel pressure was all over the
place.
> >From
> 4 to 9.5 psi.
>
> Cappy
>
>
>
>
>
>
> --
> 1/26/2007 11:11 AM
>
>
> --
> 1/27/2007 5:02 p; Features Subscriptions
href="http://www.matronics.com/Navigator?RVSouthEast-List">http://www.m
p; available via
href="http://forums.matronics.com">http://forums.matronics.com
Message 9
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|
| Subject: | Re: Fuel Pressure Fixed |
Okay, I learned something today.
Given what I know now, I'm glad mine have worked well all these years
without any bleeding that I can recall doing.
-Stormy
On 1/28/07, Ed Anderson <eanderson@carolina.rr.com> wrote:
>
> I think you are correct, Cappy. There are several states of gas that can
> exist in a liquid, some which cause worst effects than others, but in any
> case, they all appear to affect pressure measurements in a line to various
> degrees. Although, the attached refers to air in a hydraulic system the
> effects are the same in a pressurized fuel line. Note that bubbles can
> cause changes in head pressure as well as erroneous measurements and
> response delays.
>
> Ed
>
>
> ----- Original Message -----
> *From:* Steve Glasgow <willfly@carolina.rr.com>
> *To:* rvsoutheast-list@matronics.com
> *Sent:* Sunday, January 28, 2007 8:27 AM
> *Subject:* Re: RVSouthEast-List: Fuel Pressure Fixed
>
> What about compressibility of a gas verses a liquid. Water pipes have air
> trapped in them all the time to prevent hammer effect. The pressure sender
> is up the line not down the line. Pressure is correct at the engine, just
> not the pressure sender which is way above the carburetor. You may be
> correct if the sender is plumbed at the carburetor but mine isn't. All I
> know is it worked. No more oscillating fuel pressure.
>
> Stormy, are you giving us bad coordinates again?
>
> Love Cappy
>
> ----- Original Message -----
> *From:* Bill Boyd <sportav8r@gmail.com>
> *To:* rvsoutheast-list@matronics.com
> *Sent:* Sunday, January 28, 2007 8:05 AM
> *Subject:* Re: RVSouthEast-List: Fuel Pressure Fixed
>
>
> Smokey,
>
> I think the trapped air compresses until it reaches equilib. and then
> transmits all the pressure on down the line... in doing so it will
> tend to dampen any pulses (soften the water-hammer effect,
> what-have-you) but I think all the pressure will show up at the
> transducer. Enlighten me if I'm overlooking the obvious.
>
> It sounds like Cappy might have fixed his gauge but broken some law of
> physics. Typical Cappy maneuver if you ask me. Today I shall have to
> see if he messed up Bernouli and Newton's, by seeing if my wing still
> generates enough lift to fly :-)
>
> Cappy, I'd appreciate it if you wouldn't break or damage physical laws
> that the rest of us use every day, just to get your gauges reading
> correctly; that's very selfish and won't be tolerated.
>
> -Stormy
>
> On 1/28/07, Ron Schreck <ronschreck@alltel.net> wrote:
> ronschreck@alltel.net>
> >
> > Steve,
> >
> > Glad to hear you are back in the air. Actually, your problem and
> > solution makes perfect sense to me (Monday morning quarterbacking,
> > however). If your fuel and oil pressure sensors are mounted high on the
> > firewall, it only makes sense that any air trapped in the lines will
> > never bleed out (down hill) without some help. True, the trapped air
> > may transfer some measure of pressure, but being much more compressible
> > than a liquid it would certainly be a false reading. I think your
> > solution merits a mention on the RV list and perhaps a suggestion that
> > these sensors be mounted low on the firewall to avoid the problem
> > altogether. Nice work, Cappy!
> >
> > Smokey
> >
> > -----Original Message-----
> > From: owner-rvsoutheast-list-server@matronics.com
> > [mailto:owner-rvsoutheast-list-server@matronics.com] On Behalf Of Steve
> > Glasgow
> > Sent: Saturday, January 27, 2007 5:13 PM
> > To: SERV
> > Subject: RVSouthEast-List: Fuel Pressure Fixed
> >
> >
> > --> <willfly@carolina.rr.com>
> >
> > Turns out there was apparently air in the line to the sender. Probably
> > from
> > lines being open on annual.
> >
> > I flew before doing the procedure below and the fuel pressure was all
> > over
> > the place. From 4 to 9.5 psi.
> >
> > Anyway here is what to do to get the air out. Disconnect wires from
> > fuel
> > sender. Loosen sender so it can be moved by hand. Keep sender hand
> > tight
> > and turn on electric pump. Now loosen sender till fuel comes out around
> > the
> > pipe fitting. Then tighten to stop the fuel from leaking. Turn off
> > electric pump, secure sender and hook up wires. Done. From now on I
> > will
> > do this procedure whenever a fuel line is opened.
> >
> > I flew before doing this and the fuel pressure was all over the place.
> > >From
> > 4 to 9.5 psi.
> >
> > Cappy
> >
> >
> >
> >
> >
> >
> > --
> > 1/26/2007 11:11 AM
> >
> >
> > --
> > 1/27/2007 5:02 p; Features Subscriptions href="
> http://www.matronics.com/Navigator?RVSouthEast-List">http://www.mp;
> available via href="http://forums.matronics.com">
> http://forums.matronics.com*
> *
>
> *
>
> href="http://www.matronics.com/Navigator?RVSouthEast-List">http://www.matronics.com/Navigator?RVSouthEast-List
> href="http://forums.matronics.com">http://forums.matronics.com
> *
>
>
Message 10
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|
| Subject: | Re: Fuel Pressure Fixed |
Thanks ED. I knew I liked you. I think it all has to do with where the
sender is located Stormy. Mine is very high on the firewall.
Cappy
----- Original Message -----
From: Bill Boyd
To: rvsoutheast-list@matronics.com
Sent: Sunday, January 28, 2007 1:24 PM
Subject: Re: bubbles and pressure was : RVSouthEast-List: Fuel
Pressure Fixed
Okay, I learned something today.
Given what I know now, I'm glad mine have worked well all these years
without any bleeding that I can recall doing.
-Stormy
On 1/28/07, Ed Anderson <eanderson@carolina.rr.com> wrote:
I think you are correct, Cappy. There are several states of gas
that can exist in a liquid, some which cause worst effects than others,
but in any case, they all appear to affect pressure measurements in a
line to various degrees. Although, the attached refers to air in a
hydraulic system the effects are the same in a pressurized fuel line.
Note that bubbles can cause changes in head pressure as well as
erroneous measurements and response delays.
Ed
----- Original Message -----
From: Steve Glasgow
To: rvsoutheast-list@matronics.com
Sent: Sunday, January 28, 2007 8:27 AM
Subject: Re: RVSouthEast-List: Fuel Pressure Fixed
What about compressibility of a gas verses a liquid. Water pipes
have air trapped in them all the time to prevent hammer effect. The
pressure sender is up the line not down the line. Pressure is correct
at the engine, just not the pressure sender which is way above the
carburetor. You may be correct if the sender is plumbed at the
carburetor but mine isn't. All I know is it worked. No more
oscillating fuel pressure.
Stormy, are you giving us bad coordinates again?
Love Cappy
----- Original Message -----
From: Bill Boyd
To: rvsoutheast-list@matronics.com
Sent: Sunday, January 28, 2007 8:05 AM
Subject: Re: RVSouthEast-List: Fuel Pressure Fixed
<sportav8r@gmail.com>
Smokey,
I think the trapped air compresses until it reaches equilib. and
then
transmits all the pressure on down the line... in doing so it
will
tend to dampen any pulses (soften the water-hammer effect,
what-have-you) but I think all the pressure will show up at the
transducer. Enlighten me if I'm overlooking the obvious.
It sounds like Cappy might have fixed his gauge but broken some
law of
physics. Typical Cappy maneuver if you ask me. Today I shall
have to
see if he messed up Bernouli and Newton's, by seeing if my wing
still
generates enough lift to fly :-)
Cappy, I'd appreciate it if you wouldn't break or damage
physical laws
that the rest of us use every day, just to get your gauges
reading
correctly; that's very selfish and won't be tolerated.
-Stormy
On 1/28/07, Ron Schreck <ronschreck@alltel.net> wrote:
<ronschreck@alltel.net>
>
> Steve,
>
> Glad to hear you are back in the air. Actually, your problem
and
> solution makes perfect sense to me (Monday morning
quarterbacking,
> however). If your fuel and oil pressure sensors are mounted
high on the
> firewall, it only makes sense that any air trapped in the
lines will
> never bleed out (down hill) without some help. True, the
trapped air
> may transfer some measure of pressure, but being much more
compressible
> than a liquid it would certainly be a false reading. I think
your
> solution merits a mention on the RV list and perhaps a
suggestion that
> these sensors be mounted low on the firewall to avoid the
problem
> altogether. Nice work, Cappy!
>
> Smokey
>
> -----Original Message-----
> From: owner-rvsoutheast-list-server@matronics.com
> [mailto:owner-rvsoutheast-list-server@matronics.com] On Behalf
Of Steve
> Glasgow
> Sent: Saturday, January 27, 2007 5:13 PM
> To: SERV
> Subject: RVSouthEast-List: Fuel Pressure Fixed
>
>
> --> <willfly@carolina.rr.com>
>
> Turns out there was apparently air in the line to the sender.
Probably
> from
> lines being open on annual.
>
> I flew before doing the procedure below and the fuel pressure
was all
> over
> the place. From 4 to 9.5 psi.
>
> Anyway here is what to do to get the air out. Disconnect
wires from
> fuel
> sender. Loosen sender so it can be moved by hand. Keep sender
hand
> tight
> and turn on electric pump. Now loosen sender till fuel comes
out around
> the
> pipe fitting. Then tighten to stop the fuel from leaking.
Turn off
> electric pump, secure sender and hook up wires. Done. From
now on I
> will
> do this procedure whenever a fuel line is opened.
>
> I flew before doing this and the fuel pressure was all over
the place.
> >From
> 4 to 9.5 psi.
>
> Cappy
>
>
>
>
>
>
> --
> 1/26/2007 11:11 AM
>
>
> --
> 1/27/2007 5:02 p; Features Subscriptions
href="http://www.matronics.com/Navigator?RVSouthEast-List">
http://www.mp; available via href="http://forums.matronics.com">
http://forums.matronics.com
href="http://www.matronics.com/Navigator?RVSouthEast-List">
http://www.matronics.com/Navigator?RVSouthEast-List
href="http://forums.matronics.com">
http://forums.matronics.com
Message 11
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|
| Subject: | Re: Fuel Pressure Fixed |
As are mine; as high as possible. 625 glitch-free hours but who's counting
;-)
On 1/28/07, Steve Glasgow <willfly@carolina.rr.com> wrote:
>
> Thanks ED. I knew I liked you. I think it all has to do with where the
> sender is located Stormy. Mine is very high on the firewall.
>
> Cappy
>
> ----- Original Message -----
> *From:* Bill Boyd <sportav8r@gmail.com>
> *To:* rvsoutheast-list@matronics.com
> *Sent:* Sunday, January 28, 2007 1:24 PM
> *Subject:* Re: bubbles and pressure was : RVSouthEast-List: Fuel Pressure
> Fixed
>
> Okay, I learned something today.
>
> Given what I know now, I'm glad mine have worked well all these years
> without any bleeding that I can recall doing.
>
> -Stormy
>
> On 1/28/07, Ed Anderson <eanderson@carolina.rr.com> wrote:
> >
> > I think you are correct, Cappy. There are several states of gas that
> > can exist in a liquid, some which cause worst effects than others, but in
> > any case, they all appear to affect pressure measurements in a line to
> > various degrees. Although, the attached refers to air in a hydraulic system
> > the effects are the same in a pressurized fuel line. Note that bubbles can
> > cause changes in head pressure as well as erroneous measurements and
> > response delays.
> >
> > Ed
> >
> >
> >
> >
> >
> > ----- Original Message -----
> > *From:* Steve Glasgow <willfly@carolina.rr.com>
> > *To:* rvsoutheast-list@matronics.com
> > *Sent:* Sunday, January 28, 2007 8:27 AM
> > *Subject:* Re: RVSouthEast-List: Fuel Pressure Fixed
> >
> > What about compressibility of a gas verses a liquid. Water pipes have
> > air trapped in them all the time to prevent hammer effect. The pressure
> > sender is up the line not down the line. Pressure is correct at the engine,
> > just not the pressure sender which is way above the carburetor. You may
> > be correct if the sender is plumbed at the carburetor but mine isn't. All
> > I know is it worked. No more oscillating fuel pressure.
> >
> > Stormy, are you giving us bad coordinates again?
> >
> > Love Cappy
> >
> > ----- Original Message -----
> > *From:* Bill Boyd <sportav8r@gmail.com>
> > *To:* rvsoutheast-list@matronics.com
> > *Sent:* Sunday, January 28, 2007 8:05 AM
> > *Subject:* Re: RVSouthEast-List: Fuel Pressure Fixed
> >
> >
> >
> > Smokey,
> >
> > I think the trapped air compresses until it reaches equilib. and then
> > transmits all the pressure on down the line... in doing so it will
> > tend to dampen any pulses (soften the water-hammer effect,
> > what-have-you) but I think all the pressure will show up at the
> > transducer. Enlighten me if I'm overlooking the obvious.
> >
> > It sounds like Cappy might have fixed his gauge but broken some law of
> > physics. Typical Cappy maneuver if you ask me. Today I shall have to
> > see if he messed up Bernouli and Newton's, by seeing if my wing still
> > generates enough lift to fly :-)
> >
> > Cappy, I'd appreciate it if you wouldn't break or damage physical laws
> > that the rest of us use every day, just to get your gauges reading
> > correctly; that's very selfish and won't be tolerated.
> >
> > -Stormy
> >
> > On 1/28/07, Ron Schreck <ronschreck@alltel.net> wrote:
> > ronschreck@alltel.net>
> > >
> > > Steve,
> > >
> > > Glad to hear you are back in the air. Actually, your problem and
> > > solution makes perfect sense to me (Monday morning quarterbacking,
> > > however). If your fuel and oil pressure sensors are mounted high on
> > the
> > > firewall, it only makes sense that any air trapped in the lines will
> > > never bleed out (down hill) without some help. True, the trapped air
> > > may transfer some measure of pressure, but being much more
> > compressible
> > > than a liquid it would certainly be a false reading. I think your
> > > solution merits a mention on the RV list and perhaps a suggestion that
> > > these sensors be mounted low on the firewall to avoid the problem
> > > altogether. Nice work, Cappy!
> > >
> > > Smokey
> > >
> > > -----Original Message-----
> > > From: owner-rvsoutheast-list-server@matronics.com
> > > [mailto:owner-rvsoutheast-list-server@matronics.com] On Behalf Of
> > Steve
> > > Glasgow
> > > Sent: Saturday, January 27, 2007 5:13 PM
> > > To: SERV
> > > Subject: RVSouthEast-List: Fuel Pressure Fixed
> > >
> > >
> > > --> <willfly@carolina.rr.com>
> > >
> > > Turns out there was apparently air in the line to the sender.
> > Probably
> > > from
> > > lines being open on annual.
> > >
> > > I flew before doing the procedure below and the fuel pressure was all
> > > over
> > > the place. From 4 to 9.5 psi.
> > >
> > > Anyway here is what to do to get the air out. Disconnect wires from
> > > fuel
> > > sender. Loosen sender so it can be moved by hand. Keep sender hand
> > > tight
> > > and turn on electric pump. Now loosen sender till fuel comes out
> > around
> > > the
> > > pipe fitting. Then tighten to stop the fuel from leaking. Turn off
> > > electric pump, secure sender and hook up wires. Done. From now on I
> > > will
> > > do this procedure whenever a fuel line is opened.
> > >
> > > I flew before doing this and the fuel pressure was all over the place.
> > > >From
> > > 4 to 9.5 psi.
> > >
> > > Cappy
> > >
> > >
> > >
> > >
> > >
> > >
> > > --
> > > 1/26/2007 11:11 AM
> > >
> > >
> > > --
> > > 1/27/2007 5:02 p; Features Subscriptions href="
> > http://www.matronics.com/Navigator?RVSouthEast-List"> http://www.mp;
> > available via href="http://forums.matronics.com">http://forums.matronics.com
> > *
> > *
> >
> > *
> >
> > href="http://www.matronics.com/Navigator?RVSouthEast-List">
> > http://www.matronics.com/Navigator?RVSouthEast-List
> > href="http://forums.matronics.com">
> > http://forums.matronics.com
> > *
> >
> >
>
Message 12
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| Subject: | Re: Fuel Pressure Fixed |
Response delays I'll buy, Ed. In fact, I'll take water-hammer dampeners for
$50, please ;-)
There may be as many "states of gas that can exist in a liquid" as there are
ways to leave your lover, but they are all at the same pressure if they're
confined in the same hose - or I live in a parallel universe (a possibility
I will disregard for the sake of continuing to fly with you fine friends ;-)
-Stormy
On 1/28/07, Ed Anderson <eanderson@carolina.rr.com> wrote:
>
> I think you are correct, Cappy. There are several states of gas that can
> exist in a liquid, some which cause worst effects than others, but in any
> case, they all appear to affect pressure measurements in a line to various
> degrees. Although, the attached refers to air in a hydraulic system the
> effects are the same in a pressurized fuel line. Note that bubbles can
> cause changes in head pressure as well as erroneous measurements and
> response delays.
>
> Ed
>
>
> ----- Original Message -----
> *From:* Steve Glasgow <willfly@carolina.rr.com>
> *To:* rvsoutheast-list@matronics.com
> *Sent:* Sunday, January 28, 2007 8:27 AM
> *Subject:* Re: RVSouthEast-List: Fuel Pressure Fixed
>
> What about compressibility of a gas verses a liquid. Water pipes have air
> trapped in them all the time to prevent hammer effect. The pressure sender
> is up the line not down the line. Pressure is correct at the engine, just
> not the pressure sender which is way above the carburetor. You may be
> correct if the sender is plumbed at the carburetor but mine isn't. All I
> know is it worked. No more oscillating fuel pressure.
>
> Stormy, are you giving us bad coordinates again?
>
> Love Cappy
>
> ----- Original Message -----
> *From:* Bill Boyd <sportav8r@gmail.com>
> *To:* rvsoutheast-list@matronics.com
> *Sent:* Sunday, January 28, 2007 8:05 AM
> *Subject:* Re: RVSouthEast-List: Fuel Pressure Fixed
>
>
> Smokey,
>
> I think the trapped air compresses until it reaches equilib. and then
> transmits all the pressure on down the line... in doing so it will
> tend to dampen any pulses (soften the water-hammer effect,
> what-have-you) but I think all the pressure will show up at the
> transducer. Enlighten me if I'm overlooking the obvious.
>
> It sounds like Cappy might have fixed his gauge but broken some law of
> physics. Typical Cappy maneuver if you ask me. Today I shall have to
> see if he messed up Bernouli and Newton's, by seeing if my wing still
> generates enough lift to fly :-)
>
> Cappy, I'd appreciate it if you wouldn't break or damage physical laws
> that the rest of us use every day, just to get your gauges reading
> correctly; that's very selfish and won't be tolerated.
>
> -Stormy
>
> On 1/28/07, Ron Schreck <ronschreck@alltel.net> wrote:
> ronschreck@alltel.net>
> >
> > Steve,
> >
> > Glad to hear you are back in the air. Actually, your problem and
> > solution makes perfect sense to me (Monday morning quarterbacking,
> > however). If your fuel and oil pressure sensors are mounted high on the
> > firewall, it only makes sense that any air trapped in the lines will
> > never bleed out (down hill) without some help. True, the trapped air
> > may transfer some measure of pressure, but being much more compressible
> > than a liquid it would certainly be a false reading. I think your
> > solution merits a mention on the RV list and perhaps a suggestion that
> > these sensors be mounted low on the firewall to avoid the problem
> > altogether. Nice work, Cappy!
> >
> > Smokey
> >
> > -----Original Message-----
> > From: owner-rvsoutheast-list-server@matronics.com
> > [mailto:owner-rvsoutheast-list-server@matronics.com] On Behalf Of Steve
> > Glasgow
> > Sent: Saturday, January 27, 2007 5:13 PM
> > To: SERV
> > Subject: RVSouthEast-List: Fuel Pressure Fixed
> >
> >
> > --> <willfly@carolina.rr.com>
> >
> > Turns out there was apparently air in the line to the sender. Probably
> > from
> > lines being open on annual.
> >
> > I flew before doing the procedure below and the fuel pressure was all
> > over
> > the place. From 4 to 9.5 psi.
> >
> > Anyway here is what to do to get the air out. Disconnect wires from
> > fuel
> > sender. Loosen sender so it can be moved by hand. Keep sender hand
> > tight
> > and turn on electric pump. Now loosen sender till fuel comes out around
> > the
> > pipe fitting. Then tighten to stop the fuel from leaking. Turn off
> > electric pump, secure sender and hook up wires. Done. From now on I
> > will
> > do this procedure whenever a fuel line is opened.
> >
> > I flew before doing this and the fuel pressure was all over the place.
> > >From
> > 4 to 9.5 psi.
> >
> > Cappy
> >
> >
> >
> >
> >
> >
> > --
> > 1/26/2007 11:11 AM
> >
> >
> > --
> > 1/27/2007 5:02 p; Features Subscriptions href="
> http://www.matronics.com/Navigator?RVSouthEast-List">http://www.mp;
> available via href="http://forums.matronics.com">
> http://forums.matronics.com*
> *
>
> *
>
> href="http://www.matronics.com/Navigator?RVSouthEast-List">http://www.matronics.com/Navigator?RVSouthEast-List
> href="http://forums.matronics.com">http://forums.matronics.com
> *
>
>
Message 13
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| Subject: | Re: Fuel Pressure Fixed |
I agree, Stormy, if you have a steady state condition. However, when
the system environment is not static but dynamic then you can indeed
have fluctuation states that cause the state in one part of the system
to be different than another part.
Consider two rail road cars separated by a untearable bag of air,each
car with a force measuring instrument (after all pressure is simply
force over an area, right?). Then back an engine into the first car at
some rate of speed. The first car will "feel" the impact essential
instantaneously over its entire length and the force measuring device on
the first car will register the force of the impact. However, at the
same instant the force measuring sensor on the second car will register
zero force. It will continue to register zero force until the pressure
inside the air bag has increased sufficiently ( due to the compression
forces) that the compressed air is able to transmit some force to the
second car. Yes, eventually, the second car will measure the same force
as the first car - but not instantaneous, there will be a delay. Now
repeated back up the engine and ram the cars again and again and you
have a rather chaotic and dynamic system with the air compressing,
collapsing, rebounding, etc.
Therefore, you can have two different sections of the liquid
(separated by bubble(s)) that see difference forces and therefore
pressures varying in a dynamic manner. In a real fuel line the
situation is considerably more dynamic than my example.
In a fuel line with multiple bubbles the situation can be complex. You
have a pump that may be creating bubbles through caviation, you will
have some amount of air bubble being re-absorbed back into the fluid,
you have bubbles being created by pressure drops through fittings,
temperature increases, etc. You may even have a leak that permits air
into the system. So depending on the level your are viewing it at -what
may appear to be a steady state system is its anything but a steady
state system.
Air in fluid lines is generally not a good thing - just how bad the
effect can - depends on a number of variables.
But, if you have had no problems - then I certainly wouldn't worry about
all those little bubbles {:>)
my 0.02 and I'm off to bed
Ed
----- Original Message -----
From: Bill Boyd
To: rvsoutheast-list@matronics.com
Sent: Sunday, January 28, 2007 9:28 PM
Subject: Re: bubbles and pressure was : RVSouthEast-List: Fuel
Pressure Fixed
Response delays I'll buy, Ed. In fact, I'll take water-hammer
dampeners for $50, please ;-)
There may be as many "states of gas that can exist in a liquid" as
there are ways to leave your lover, but they are all at the same
pressure if they're confined in the same hose - or I live in a parallel
universe (a possibility I will disregard for the sake of continuing to
fly with you fine friends ;-)
-Stormy
On 1/28/07, Ed Anderson <eanderson@carolina.rr.com> wrote:
I think you are correct, Cappy. There are several states of gas
that can exist in a liquid, some which cause worst effects than others,
but in any case, they all appear to affect pressure measurements in a
line to various degrees. Although, the attached refers to air in a
hydraulic system the effects are the same in a pressurized fuel line.
Note that bubbles can cause changes in head pressure as well as
erroneous measurements and response delays.
Ed
----- Original Message -----
From: Steve Glasgow
To: rvsoutheast-list@matronics.com
Sent: Sunday, January 28, 2007 8:27 AM
Subject: Re: RVSouthEast-List: Fuel Pressure Fixed
What about compressibility of a gas verses a liquid. Water pipes
have air trapped in them all the time to prevent hammer effect. The
pressure sender is up the line not down the line. Pressure is correct
at the engine, just not the pressure sender which is way above the
carburetor. You may be correct if the sender is plumbed at the
carburetor but mine isn't. All I know is it worked. No more
oscillating fuel pressure.
Stormy, are you giving us bad coordinates again?
Love Cappy
----- Original Message -----
From: Bill Boyd
To: rvsoutheast-list@matronics.com
Sent: Sunday, January 28, 2007 8:05 AM
Subject: Re: RVSouthEast-List: Fuel Pressure Fixed
<sportav8r@gmail.com>
Smokey,
I think the trapped air compresses until it reaches equilib. and
then
transmits all the pressure on down the line... in doing so it
will
tend to dampen any pulses (soften the water-hammer effect,
what-have-you) but I think all the pressure will show up at the
transducer. Enlighten me if I'm overlooking the obvious.
It sounds like Cappy might have fixed his gauge but broken some
law of
physics. Typical Cappy maneuver if you ask me. Today I shall
have to
see if he messed up Bernouli and Newton's, by seeing if my wing
still
generates enough lift to fly :-)
Cappy, I'd appreciate it if you wouldn't break or damage
physical laws
that the rest of us use every day, just to get your gauges
reading
correctly; that's very selfish and won't be tolerated.
-Stormy
On 1/28/07, Ron Schreck <ronschreck@alltel.net> wrote:
<ronschreck@alltel.net>
>
> Steve,
>
> Glad to hear you are back in the air. Actually, your problem
and
> solution makes perfect sense to me (Monday morning
quarterbacking,
> however). If your fuel and oil pressure sensors are mounted
high on the
> firewall, it only makes sense that any air trapped in the
lines will
> never bleed out (down hill) without some help. True, the
trapped air
> may transfer some measure of pressure, but being much more
compressible
> than a liquid it would certainly be a false reading. I think
your
> solution merits a mention on the RV list and perhaps a
suggestion that
> these sensors be mounted low on the firewall to avoid the
problem
> altogether. Nice work, Cappy!
>
> Smokey
>
> -----Original Message-----
> From: owner-rvsoutheast-list-server@matronics.com
> [mailto:owner-rvsoutheast-list-server@matronics.com] On Behalf
Of Steve
> Glasgow
> Sent: Saturday, January 27, 2007 5:13 PM
> To: SERV
> Subject: RVSouthEast-List: Fuel Pressure Fixed
>
>
> --> <willfly@carolina.rr.com>
>
> Turns out there was apparently air in the line to the sender.
Probably
> from
> lines being open on annual.
>
> I flew before doing the procedure below and the fuel pressure
was all
> over
> the place. From 4 to 9.5 psi.
>
> Anyway here is what to do to get the air out. Disconnect
wires from
> fuel
> sender. Loosen sender so it can be moved by hand. Keep sender
hand
> tight
> and turn on electric pump. Now loosen sender till fuel comes
out around
> the
> pipe fitting. Then tighten to stop the fuel from leaking.
Turn off
> electric pump, secure sender and hook up wires. Done. From
now on I
> will
> do this procedure whenever a fuel line is opened.
>
> I flew before doing this and the fuel pressure was all over
the place.
> >From
> 4 to 9.5 psi.
>
> Cappy
>
>
>
>
>
>
> --
> 1/26/2007 11:11 AM
>
>
> --
> 1/27/2007 5:02 p; Features Subscriptions
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