X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Mon, 16 May 2011 09:39:05 -0400 Message-ID: X-Original-Return-Path: Received: from s6.cableone.net ([24.116.0.232] verified) by logan.com (CommuniGate Pro SMTP 5.4c3j) with ESMTP id 4985025 for lml@lancaironline.net; Mon, 16 May 2011 07:03:45 -0400 Received-SPF: pass receiver=logan.com; client-ip=24.116.0.232; envelope-from=bbreen@cableone.net Received: from [192.168.1.104] (unverified [96.19.144.204]) by s6.cableone.net (CableOne SMTP Service s6) with ESMTP id 42066680-1872270 for ; Mon, 16 May 2011 04:03:08 -0700 X-Original-Return-Path: Subject: Re: [LML] Re: Fuel restriction or air? References: From: Berni Content-Type: text/plain; charset=us-ascii X-Mailer: iPad Mail (8H7) In-Reply-To: X-Original-Message-Id: <59816633-74AC-4ACD-999A-57195062104A@cableone.net> X-Original-Date: Mon, 16 May 2011 06:03:08 -0500 X-Original-To: Lancair Mailing List Content-Transfer-Encoding: quoted-printable Mime-Version: 1.0 (iPad Mail 8H7) X-Vpipe: Scanner said ok (av_avast) X-IP-stats: Incoming Last 0, First 2, in=2, out=0, spam=0 ip=96.19.144.204 X-Originating-IP: 96.19.144.204 X-Abuse-Info: Send abuse complaints to abuse@cableone.net Yes, all of these have been checked and verified to be working properly. Sent from my iPad Berni Breen Bbreen@cableone.net On May 15, 2011, at 7:48 PM, Colyn Case wrote: > Did you verify the fuel vents are working properly? ....and that the che= ck valves on the vents are oriented correctly? >=20 > Also - what were the ambient temperatures? >=20 > Another more far out issue: Is there a heat source in the engine compart= ment aimed at any fuel lines? e.g. on my IV-P if the joints on the transfe= r tube leak, the gascolator and associated plumbing get the heat. (Although= I now have wrapped them in heat resistant covering). >=20 > On May 15, 2011, at 8:04 AM, Berni wrote: >=20 >> I have been trying to chase down the cause of a fuel issue in my normally= aspirated Lancair IV engine. During a cross country flight my fuel flow in= dicator began to show fluctuations which I mistakenly believed to be false r= eadings. Shortly thereafter during the same flight the engine began surging= , slightly at first but increasingly worse in short time. So much so that I= began to plan for an emergency landing as I was looking to find the cause a= nd to introduce a remedy. I turned on my electric (back up) fuel pump and t= he engine immediately began to run strong and the fluctuation readings stabi= lized. =20 >>=20 >> After gaining altitude I turned off the electric pump and the unstable fu= el flow readings as well as the engine surge returned. >>=20 >> My initial take was that my problem was caused by a failing engine driven= fuel pump. Even with that belief (once back on the ground) I checked as mu= ch of the fuel system as possible looking for potential restrictions. I loo= ked at and cleaned the screens at the wing root connections as well as the i= nlet on the GAMI injectors. I found no restrictions so I removed and exchan= ged my engine driven pump for a rebuilt unit. >>=20 >> After installing the rebuilt pump the engine tested fine on the ground an= d fine in the air on a subsequent cross country trip. Approximately 2.1 hou= rs of flying time later the exact same symptoms returned...erratic fuel flow= readings followed closely by engine surge. >>=20 >> I am now at a loss as to what I should now look for. Could my problem be= due to air somehow being introduced into my fuel flow? Should I be looking= at my fuel selector as a possible culprit? If so how would I test that pos= sibility? >>=20 >> Any and all suggestions would be most appreciated. >>=20 >> Sent from my iPad >> Berni Breen >> Bbreen@cableone.net >> -- >> For archives and unsub http://mail.lancaironline.net:81/lists/lml/List.ht= ml >=20 >=20 > -- > For archives and unsub http://mail.lancaironline.net:81/lists/lml/List.htm= l