Today's Message Index:
----------------------
1. 10:10 AM - Re: Low fuel pressure indication (HCRV6@comcast.net)
2. 11:54 AM - Low fuel pressure injected engine (Michele Delsol)
3. 12:19 PM - Re: IFR RVs in the US (Michele Delsol)
4. 12:21 PM - Re: Low fuel pressure injected engine (Linn Walters)
5. 12:35 PM - Re: Low fuel pressure injected engine (Tracy)
6. 10:27 PM - Re: Low fuel pressure injected engine (Robin Marks)
Message 1
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Subject: | Re: Low fuel pressure indication |
Thanks Mike, excellent point that was escaping me.
Harry
----- Original Message -----
From: "Mike Robertson" <mrobert569@hotmail.com>
Sent: Thursday, June 27, 2013 11:25:15 AM
Subject: RE: RV-List: Low fuel pressure indication
Harry,
Keep in mind that when we measure pressure we are really talking pressure differential.
If the throttle is full open then the fuel pressure differential may
actually be zero. For carb equipped airplanes I would not get too carried away
with a zero reading at full throttle as long as the engine is running good and
you still see some pressure when you turn on the boost pump.
Mike Robertson
From: HCRV6@comcast.net
Subject: RV-List: Low fuel pressure indication
I have a puzzling problem and wondering if anyone can shed some light on it. Under
continuous high power settings, like in climb to altitude after takeoff, my
Grand Rapids EFIS fuel pressure indication drops to zero and even shows a low
negative value after a couple of minutes, but the engine continues to run at
full power. This with a carbureted O-360 and running on the engine driven pump
only. If I switch the aux pump back on the pressure indication comes back to
the normal 2 to 4 psi range. I had this problem a few years ago and installing
a new VDO pressure sender from Grand Rapids cured it, but this time a new sender
did not help. The pressure take off is at the carburetor and the sender is
mounted on the firewall, connected with a -2 hose.
The thing that has me scratching my head is that the engine keeps running fine
at high fuel flow even though the fuel pressure indicates zero or less, so I would
suspect a bum sender again, but the fact that the pressure indication comes
back to normal when I turn the aux pump back on has me baffled.
Harry Crosby
RV-6 N16CX, 1080 hours
get=_blank>http://www.matronics.com/Navigator?RV-List
ttp://forums.matronics.com
Message 2
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Subject: | Low fuel pressure injected engine |
Hello to all,
While the subject is on fuel pressure (carbureted engine) I thought
I=92d
relate a little problem I am encountering on occasion in my fuel
injected
engine.
I=92d be putting along at cruise speed when all of a sudden, some slight
misfire, loss of poser. I look at the fuel pressure and it is down from
26
psi to the low teens. A slight touch of the boost pump and the problem
disappears. Turn the boost pump off and the pressure continues up there
at
27 psi and I can continue and hour or more ' no incident.
Set up : TMX-360 (AKA IO-360), Precision Airmotive Silver Hawk Fuel
injection, standard injectors. Pmag and Slick. I run at 24/2400 8 USG/hr
and
get 150 knts ias.
Temporary vapor lock ? Mechanical fuel pump is beginning to have
problems ?
It=92s a glitch ' it does not happen on all flights and does not seem
related
to outside air temp. Any ideas ???
This does not keep me from flying but since the boost pump has become a
life
line, I am installing Andair=92s new fuel pump in line with the boost
pump as
a back up boost pump in case things get a little nasty.
Regards,
Mich=E8le
RV8 ' TMX-360
Message 3
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Subject: | IFR RVs in the US |
I knew I=92d get knowledgeable responses from the list ' you guys are
great.
Such good stuff, thanks. Gives me the ammo to approach the French
authorities ' they really treat us like children ' no trust. They
want us to
have just about everything certified : engine and everything that goes
on
one, all avionics, gages, why not switches, breakers, wiring=85 with the
appropriate form One=92s on each item. Maintenance in a certified shop
and the
paper work to go along... Result ' there are no Night or IFR home
builts in
France ' there is one exception which proves the rule.
Thanks ' i=92ll work with the material/info you sent and would get
back off
line if I need clarifications.
Mich=E8le
De : owner-rv-list-server@matronics.com
[mailto:owner-rv-list-server@matronics.com] De la part de Michele Delsol
Envoy=E9 : lundi 24 juin 2013 22:04
=C0 : rv-list@matronics.com
Objet : RV-List: IFR RVs in the US
Hello to all,
I=92ve been lurking on the sidelines of this list and have contributed
at
times during the build time of my RV8 ' from France. I have finished
the 8
which has been providing me with more joy than I anticipated. What a
great
airplane.
All would be perfect except that the French and most Europeans do not
allow
home builts to fly IFR. A few of the RV owners being military and/or
professional pilots with full IFR qualifications, with planes very well
equipped avionics wise, would like to change this. I have thus taken it
upon
myself within the context of our French RV builder group
(www.vansclubdefrance.fr) to explore the possibility of having the rules
changed, at least within the context of French skies.
Since the US FAA does allow experimental built airplanes to fly IFR in
the
US, my question to the list is : what are the criteria which would allow
an
RV to be flown IFR by a duly qualified IFR pilot ? Questions which come
to
mind are :
=B7 Does the engine have to be certified as opposed to a non
certified
such as Mattituck, Superior, Barret=85 ?
=B7 What about maintenance ' by certified mechanic or by owner
under a
certain conditions ?
=B7 Minimum avionics : ex. two radios, VORs, DME, other ?
=B7 Any steam gages ?
=B7 Does the owner who does his own maintenance have to acquire
specific qualifications ?
Thanks,
Mich=E8le Delsol
RV8 ' F-PDSL
Message 4
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Subject: | Re: Low fuel pressure injected engine |
On 6/28/2013 2:56 PM, Michele Delsol wrote:
>
> Hello to all,
>
> While the subject is on fuel pressure (carbureted engine) I thought
> I'd relate a little problem I am encountering on occasion in my fuel
> injected engine.
>
> I'd be putting along at cruise speed when all of a sudden, some slight
> misfire, loss of poser. I look at the fuel pressure and it is down
> from 26 psi to the low teens. A slight touch of the boost pump and the
> problem disappears. Turn the boost pump off and the pressure continues
> up there at 27 psi and I can continue and hour or more -- no incident.
>
> Set up : TMX-360 (AKA IO-360), Precision Airmotive Silver Hawk Fuel
> injection, standard injectors. Pmag and Slick. I run at 24/2400 8
> USG/hr and get 150 knts ias.
>
> Temporary vapor lock ?
>
Unlikely in cruise.
>
> Mechanical fuel pump is beginning to have problems ?
>
That's possible. There could be something that gets caught in the pump
valve(s) that's put back in it's 'resting place' when you turn the
electric pump on. Just speculation ......
>
> It's a glitch -- it does not happen on all flights and does not seem
> related to outside air temp. Any ideas ???
>
You might try changes in throttle or mixture to see it that changes
anything before using the electric pump. Let us know what you find.
Linn
>
> This does not keep me from flying but since the boost pump has become
> a life line, I am installing Andair's new fuel pump in line with the
> boost pump as a back up boost pump in case things get a little nasty.
>
> Regards,
>
> Michle
>
> RV8 -- TMX-360
>
> *
>
>
> *
>
> No virus found in this message.
> Checked by AVG - www.avg.com <http://www.avg.com>
>
Message 5
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Subject: | Re: Low fuel pressure injected engine |
That is a mystery. But if the problem gets even slightly worse ( with old &
new boost pumps off) the likelihood of vapor lock as the problem is pretty h
igh. Any increase in flow resistance at that point in the system will make m
atters worse.
FWIW, many aircraft fuel systems are an excuse for vapor lock to happen. It
's no wonder using auto fuel pushes them over the edge.
Tracy Crook
2000+ hours on auto fuel without vapor lock.
Sent from my iPad
On Jun 28, 2013, at 12:56, "Michele Delsol" <mdelsol@md-dsl.fr> wrote:
> Hello to all,
>
> While the subject is on fuel pressure (carbureted engine) I thought I
=99d relate a little problem I am encountering on occasion in my fuel inject
ed engine.
>
> I=99d be putting along at cruise speed when all of a sudden, some sl
ight misfire, loss of poser. I look at the fuel pressure and it is down from
26 psi to the low teens. A slight touch of the boost pump and the problem d
isappears. Turn the boost pump off and the pressure continues up there at 27
psi and I can continue and hour or more =93 no incident.
>
> Set up : TMX-360 (AKA IO-360), Precision Airmotive Silver Hawk Fuel injec
tion, standard injectors. Pmag and Slick. I run at 24/2400 8 USG/hr and get 1
50 knts ias.
>
> Temporary vapor lock ? Mechanical fuel pump is beginning to have problems ?
It=99s a glitch =93 it does not happen on all flights and does n
ot seem related to outside air temp. Any ideas ???
>
> This does not keep me from flying but since the boost pump has become a li
fe line, I am installing Andair=99s new fuel pump in line with the boo
st pump as a back up boost pump in case things get a little nasty.
>
> Regards,
> Mich=C3=A8le
> RV8 =93 TMX-360
>
>
>
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>
Message 6
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Subject: | Low fuel pressure injected engine |
Mich=E8le
Do you know your TAS at those settings?
Robin
From: owner-rv-list-server@matronics.com [mailto:owner-rv-list-server@matro
nics.com] On Behalf Of Michele Delsol
Sent: Friday, June 28, 2013 11:57 AM
Subject: RV-List: Low fuel pressure injected engine
Hello to all,
While the subject is on fuel pressure (carbureted engine) I thought I'd rel
ate a little problem I am encountering on occasion in my fuel injected engi
ne.
I'd be putting along at cruise speed when all of a sudden, some slight misf
ire, loss of poser. I look at the fuel pressure and it is down from 26 psi
to the low teens. A slight touch of the boost pump and the problem disappea
rs. Turn the boost pump off and the pressure continues up there at 27 psi a
nd I can continue and hour or more - no incident.
Set up : TMX-360 (AKA IO-360), Precision Airmotive Silver Hawk Fuel inject
ion, standard injectors. Pmag and Slick. I run at 24/2400 8 USG/hr and get
150 knts ias.
Temporary vapor lock ? Mechanical fuel pump is beginning to have problems ?
It's a glitch - it does not happen on all flights and does not seem relate
d to outside air temp. Any ideas ???
This does not keep me from flying but since the boost pump has become a lif
e line, I am installing Andair's new fuel pump in line with the boost pump
as a back up boost pump in case things get a little nasty.
Regards,
Mich=E8le
RV8 - TMX-360
________________________________
No virus found in this message.
Checked by AVG - www.avg.com<http://www.avg.com>
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