---------------------------------------------------------- RV-List Digest Archive --- Total Messages Posted Fri 06/28/13: 6 ---------------------------------------------------------- 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 _____________________________________ Time: 10:10:56 AM PST US From: HCRV6@comcast.net Subject: Re: RV-List: Low fuel pressure indication Thanks Mike, excellent point that was escaping me. Harry ----- Original Message ----- From: "Mike Robertson" 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 _____________________________________ Time: 11:54:14 AM PST US From: "Michele Delsol" Subject: RV-List: 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 _____________________________________ Time: 12:19:34 PM PST US From: "Michele Delsol" Subject: RE: RV-List: 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 _____________________________________ Time: 12:21:00 PM PST US From: Linn Walters Subject: Re: RV-List: 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 > ________________________________ Message 5 _____________________________________ Time: 12:35:41 PM PST US Subject: Re: RV-List: Low fuel pressure injected engine From: Tracy 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" 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 > > > ========================== ========= ========================== ========= ========================== ========= ========================== ========= > ________________________________ Message 6 _____________________________________ Time: 10:27:27 PM PST US From: Robin Marks Subject: RE: RV-List: 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. 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