---------------------------------------------------------- JabiruEngine-List Digest Archive --- Total Messages Posted Sun 04/06/08: 5 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 02:24 PM - Fuel Pressure Question? (Jeffrey J Paris) 2. 02:43 PM - Re: Electrical Newbie Question (jetboy) 3. 02:46 PM - Re: Fuel Pressure Question? (Peter Harris) 4. 03:35 PM - Re: Fuel Pressure Question? (Craig Payne) 5. 04:03 PM - Re: Fuel Pressure Question? (Lancaster Aero Ltd) ________________________________ Message 1 _____________________________________ Time: 02:24:14 PM PST US Subject: JabiruEngine-List: Fuel Pressure Question? From: "Jeffrey J Paris" Dear Jabiru Engine Wonks, I have a question about fuel pressure and fuel flow. I currently own and fly a Zenith CH601XL equipped with a Jab 3300, I have about 192 hours on AF/PP. I am fortunate in flying with a fully TSO'd Xerion Auracle Engine monitor/analyzer. My two last flights I have noted some peculiarities with fuel pressure and fuel flow while flying. My engine analyzer at altitude sends up a warning message that fuel pressure is low/lowering and while all seems to be running right I noticed that my fuel flow numbers were going up? When I turn on my Facet boost pump the fuel pressure would go back into the normal green values and the fuel flow returns back to a respectable number. Furthermore, while flying on the way home my engine analyzer started this curious behavior again. While slowly descending into my home airport I reduced power and watched everything come into sync. What got my attention next was that I felt the engine sort of "burp" or skip a bit. I pulled carb. heat and turned on the boost pump to cover my rear end. It was enough of a "burp" for me to take notice. So with that information in hand, what does this mean? You would think that low fuel pressure would = lowering fuel flow right? Conversely, the opposite should apply ... Does anyone here know what I'm dealing with other than that she's running beautifully. Thank you for you time and consideration. Jeff Paris N196ZP KSDC Williamson-Sodus CH601XL Jabiru 3300 _______________________________________________ Join Excite! - http://www.excite.com The most personalized portal on the Web! ________________________________ Message 2 _____________________________________ Time: 02:43:58 PM PST US Subject: JabiruEngine-List: Re: Electrical Newbie Question From: "jetboy" Tim, you will need to disconnect both wires if you want to isolate the regulator due to some fault, simply because you wont know which wire is carrying / causing the fault. The yellow wire should be bonded to the red wire at the regulator, and the extended lead can go via a fuse, fuse link or cct breaker to the batt +ve. This is the safest option and the recommended wiring method as written in the current Jabiru installation manual. I think Bob's Z20? is the most recent diagram -equally safe and with more protective measures and features. Ralph -------- Ralph - CH701 / 2200a Read this topic online here: http://forums.matronics.com/viewtopic.php?p=175117#175117 ________________________________ Message 3 _____________________________________ Time: 02:46:33 PM PST US From: "Peter Harris" Subject: RE: JabiruEngine-List: Fuel Pressure Question? Jeffry I have spent some time investigating the fuel flow of my J3300 and found as follows: The needle valve seat provided by Jabiru is 2.25mm and is meant for gravity feed. It leaks from about 2700 rpm causing the fuel bowl to get above design level and the engine to run rich . Excessive rich running causes decreased power and rough running very noticeable if it occurs in flight. The correct needle seat for a fuel pump fed installation is 1.5mm and I fitted one of these. It ran too lean at WOT but when I started the boost pump it also leaked and I saw 36LPH on my Navman fuel flow meter. I have discussed this issue with the Jab engine shop and understand that the setup is tuned for the typical Jabiru installation and that needles and jets were chosen to provide best cruise mix at about 2750 and excessive rich mix at higher RPM and at WOT as a measure to ensure the valves are kept cool. It may possibly be that you are experiencing patchy over rich running. Peter H -----Original Message----- From: owner-jabiruengine-list-server@matronics.com [mailto:owner-jabiruengine-list-server@matronics.com] On Behalf Of Jeffrey J Paris Sent: Monday, 7 April 2008 7:19 AM Subject: JabiruEngine-List: Fuel Pressure Question? Dear Jabiru Engine Wonks, I have a question about fuel pressure and fuel flow. I currently own and fly a Zenith CH601XL equipped with a Jab 3300, I have about 192 hours on AF/PP. I am fortunate in flying with a fully TSO'd Xerion Auracle Engine monitor/analyzer. My two last flights I have noted some peculiarities with fuel pressure and fuel flow while flying. My engine analyzer at altitude sends up a warning message that fuel pressure is low/lowering and while all seems to be running right I noticed that my fuel flow numbers were going up? When I turn on my Facet boost pump the fuel pressure would go back into the normal green values and the fuel flow returns back to a respectable number. Furthermore, while flying on the way home my engine analyzer started this curious behavior again. While slowly descending into my home airport I reduced power and watched everything come into sync. What got my attention next was that I felt the engine sort of "burp" or skip a bit. I pulled carb. heat and turned on the boost pump to cover my rear end. It was enough of a "burp" for me to take notice. So with that information in hand, what does this mean? You would think that low fuel pressure would = lowering fuel flow right? Conversely, the opposite should apply ... Does anyone here know what I'm dealing with other than that she's running beautifully. Thank you for you time and consideration. Jeff Paris N196ZP KSDC Williamson-Sodus CH601XL Jabiru 3300 _______________________________________________ Join Excite! - http://www.excite.com The most personalized portal on the Web! ________________________________ Message 4 _____________________________________ Time: 03:35:53 PM PST US From: "Craig Payne" Subject: RE: JabiruEngine-List: Fuel Pressure Question? Where is your fuel pressure sender? Between the mechanical pump and the engine? If so think of it this way: with a pump working against a dead-end pipe you would have the maximum pressure and no flow. As soon as you allow fuel to flow the pressure will drop and the flow rise. -- Craig -----Original Message----- From: owner-jabiruengine-list-server@matronics.com [mailto:owner-jabiruengine-list-server@matronics.com] On Behalf Of Jeffrey J Paris Sent: Sunday, April 06, 2008 3:19 PM Subject: JabiruEngine-List: Fuel Pressure Question? Dear Jabiru Engine Wonks, I have a question about fuel pressure and fuel flow. I currently own and fly a Zenith CH601XL equipped with a Jab 3300, I have about 192 hours on AF/PP. I am fortunate in flying with a fully TSO'd Xerion Auracle Engine monitor/analyzer. My two last flights I have noted some peculiarities with fuel pressure and fuel flow while flying. My engine analyzer at altitude sends up a warning message that fuel pressure is low/lowering and while all seems to be running right I noticed that my fuel flow numbers were going up? When I turn on my Facet boost pump the fuel pressure would go back into the normal green values and the fuel flow returns back to a respectable number. Furthermore, while flying on the way home my engine analyzer started this curious behavior again. While slowly descending into my home airport I reduced power and watched everything come into sync. What got my attention next was that I felt the engine sort of "burp" or skip a bit. I pulled carb. heat and turned on the boost pump to cover my rear end. It was enough of a "burp" for me to take notice. So with that information in hand, what does this mean? You would think that low fuel pressure would = lowering fuel flow right? Conversely, the opposite should apply ... Does anyone here know what I'm dealing with other than that she's running beautifully. Thank you for you time and consideration. Jeff Paris N196ZP KSDC Williamson-Sodus CH601XL Jabiru 3300 _______________________________________________ Join Excite! - http://www.excite.com The most personalized portal on the Web! ________________________________ Message 5 _____________________________________ Time: 04:03:34 PM PST US From: Lancaster Aero Ltd Subject: Re: JabiruEngine-List: Fuel Pressure Question? Dear Sir: I'm sorry but the two people that could help you, are in Florida at the Sun & Fun air show. They should be back on April 15. Stan or Gord will email you as soon as possible. Yvonne At 05:18 PM 4/6/2008 -0400, you wrote: > > > >Dear Jabiru Engine Wonks, > >I have a question about fuel pressure and fuel flow. I currently >own and fly a Zenith CH601XL equipped with a Jab 3300, I have about >192 hours on AF/PP. I am fortunate in flying with a fully TSO'd >Xerion Auracle Engine monitor/analyzer. My two last flights I have >noted some peculiarities with fuel pressure and fuel flow while flying. > > My engine analyzer at altitude sends up a warning message that > fuel pressure is low/lowering and while all seems to be running > right I noticed that my fuel flow numbers were going up? When I > turn on my Facet boost pump the fuel pressure would go back into > the normal green values and the fuel flow returns back to a respectable number. > >Furthermore, while flying on the way home my engine analyzer >started this curious behavior again. While slowly descending into my >home airport I reduced power and watched everything come into >sync. What got my attention next was that I felt the engine sort of >"burp" or skip a bit. I pulled carb. heat and turned on the boost >pump to cover my rear end. It was enough of a "burp" for me to take notice. > >So with that information in hand, what does this mean? You would >think that low fuel pressure would = lowering fuel flow >right? Conversely, the opposite should apply ... Does anyone here >know what I'm dealing with other than that she's running beautifully. > >Thank you for you time and consideration. > >Jeff Paris >N196ZP KSDC Williamson-Sodus >CH601XL Jabiru 3300 > > >_______________________________________________ >Join Excite! - http://www.excite.com >The most personalized portal on the Web! > > >-- >Checked by AVG. >4/5/2008 7:53 AM Lancaster Aero Ltd. 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