X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Tue, 25 Aug 2009 06:17:43 -0400 Message-ID: X-Original-Return-Path: Received: from elasmtp-kukur.atl.sa.earthlink.net ([209.86.89.65] verified) by logan.com (CommuniGate Pro SMTP 5.2.16) with ESMTP id 3823553 for lml@lancaironline.net; Tue, 25 Aug 2009 00:49:24 -0400 Received-SPF: none receiver=logan.com; client-ip=209.86.89.65; envelope-from=douglasbrunner@earthlink.net DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=dk20050327; d=earthlink.net; b=otn81s3hLyyKI0dEFyzt4okvtHxcnehvn1zqGacc3ehsHlZnHqi5vJ6jtEeFr622; h=Message-ID:Date:From:Reply-To:To:Subject:Mime-Version:Content-Transfer-Encoding:X-Mailer:Content-Type:X-ELNK-Trace:X-Originating-IP; Received: from [209.86.224.42] (helo=elwamui-muscovy.atl.sa.earthlink.net) by elasmtp-kukur.atl.sa.earthlink.net with esmtpa (Exim 4.67) (envelope-from ) id 1Mfnxg-0002S2-HI for lml@lancaironline.net; Tue, 25 Aug 2009 00:48:48 -0400 Received: from 70.17.7.2 by webmail.earthlink.net with HTTP; Tue, 25 Aug 2009 00:48:48 -0400 X-Original-Message-ID: <3422164.1251175728545.JavaMail.root@elwamui-muscovy.atl.sa.earthlink.net> X-Original-Date: Tue, 25 Aug 2009 00:48:48 -0400 (GMT-04:00) From: Douglas Brunner Reply-To: Douglas Brunner X-Original-To: Lancair Mailing List Subject: Re: [LML] Fuel Flow Issue Solved Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Mailer: EarthLink Zoo Mail 1.0 Content-Type: text/html; charset=UTF-8 X-ELNK-Trace: ad85a799c4f5de37c2eb1477c196d22294f5150ab1c16ac0d64a9adbca5b3d7c7829723cd90e769d95a8c7276a23d86f350badd9bab72f9c350badd9bab72f9c X-Originating-IP: 209.86.224.42 Here is how I currently operate my IO-550 on a Legacy.
Low Boost on for takeoff and landing.  Low boost on over 9,000 f= or vapor suppression.

Low Boost for takeoff and landing is the recom= mendation of my HIPAT instructors (Ernie and Josh).  I had not had any= problems not using low boost but what the heck, it is easy enough to do an= d if it prevents a loss of power on takeoff or landing it is worth it.
<= br>Low boost on over 10,000 is recommended by many.  I did not use to = do it, but have noticed some surging as low as 9,000 if I do not.
I have= been told that this is particularly a problem on hot days and is due to hi= gh vapor pressure of hot fuel combined with the lower ambient pressure at a= ltitude.


-----Original Message-----
From: Scott Keighan
Sent: Aug 24, 2009 10:25 PM
To: lml@lancaironline.net
Subject: [LML] Fuel Flow Issue Solved

Hello Everyone,
 
I just thought I would update everyone= on my Fuel=20 Flow issue.
 About a month back I asked for a= dvise about a=20 sudden lack of fuel flow.
Where I used to get 20-21gph on Take o= ff I has=20 suddenly getting 12-14gph.
All run ups were normal but when apply= ing full=20 power for takeoff I would not
get enough flow.  When initiating= the Electric=20 fuel pump everything turned to
normal.
 
Well this problem turned into quit the= hunt to find=20 the issue.
To make a long story short I had disas= sembled and=20 reassembled the majority of
the fuel system from the:
Engine driven fuel pump
Throttle control unit
Manifold spider valve
Injectors and lines
gascolator
fuel flow meter
all fuel lines
tank vents
Electric fuel pump
 
What did it come down to??
 
A broken O-ring on the inlet side of t= he Electric=20 Fuel pump fitting.
Air was being sucked into the system.&= nbsp; I=20 finally discovered it by putting a vaccum
on the fuel lines from the engine to t= he=20 tanks.  When a vaccum could not be held
I traced it to the O-ring.
 
Four weeks of down time and= =20 about 80hrs of work to find the .50 cent problem.
Of course I had to reset all my flows = of which I=20 now get 24gph and 22psi on Takeoff.
 
Now I am still not using my Electric B= oost for Take=20 Off.  Should I or should I not???
What is the concensis of people i= n the=20 know.
 
Thanks to everyone whom gave me some= =20 input.
 
Scott Keighan
L-IV   IO-550G &= nbsp;