X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Sat, 17 Apr 2010 22:21:39 -0400 Message-ID: X-Original-Return-Path: Received: from exprod7og121.obsmtp.com ([64.18.2.20] verified) by logan.com (CommuniGate Pro SMTP 5.3.5) with SMTP id 4224882 for lml@lancaironline.net; Sat, 17 Apr 2010 16:40:20 -0400 Received-SPF: none receiver=logan.com; client-ip=64.18.2.20; envelope-from=jsocolof@pinpointamerica.com Received: from source ([64.61.31.206]) by exprod7ob121.postini.com ([64.18.6.12]) with SMTP ID DSNKS8ockKYAAs1Nr60/mpOf5G7ihLWvX27w@postini.com; Sat, 17 Apr 2010 13:40:20 PDT X-Ninja-PIM: Scanned by Ninja Received: from jsocolof ([10.1.1.21]) by mail.fins.org with Microsoft SMTPSVC(6.0.3790.1830); Sat, 17 Apr 2010 16:55:17 -0400 From: "Jon Socolof" X-Original-To: Subject: Fuel Pressure X-Original-Date: Sat, 17 Apr 2010 16:35:47 -0400 X-Original-Message-ID: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_000C_01CADE4C.088F72E0" X-Mailer: Microsoft Office Outlook 11 Thread-Index: AcrebY8WlM+7A3TJTdSg65PNZOHuUw== X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 X-Original-Return-Path: jsocolof@ershire.com X-OriginalArrivalTime: 17 Apr 2010 20:55:17.0609 (UTC) FILETIME=[49029590:01CADE70] This is a multi-part message in MIME format. ------=_NextPart_000_000C_01CADE4C.088F72E0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Ok, after going back and forth on this, here is my untrained analysis of the information I could cull on this subject. On my IO-550N fuel pressure can be measured both metered and unmetered. Unmetered fuel pressure measured between the fuel pump and fuel servo will show pressure supplied to the engine or fuel pump output. Metered pressure measured from the flow divider will show pressure wanted by the engine and will vary with throttle position. It would seem the interest here is that the supply pump is working properly, a situation that could be clouded by the variability in pressure caused by throttle and mixture position if sensed at the flow divider. A low or high unmetered fuel pressure would indicate the engine is not being supplied with enough or too much fuel and this seems like the more critical information. The gauge port on the flow divider for metered fuel pressure seems to be used primarily to drive a pressure type fuel flow gauge not applicable in my case. I will be re-plumbing to measure unmetered fuel pressure as this is what Garmin values are set to on the G900 EIS for Continentals (Garmin measures metered fuel pressure on Lycoming engines). I hope this makes sense. Jon Socolof ------=_NextPart_000_000C_01CADE4C.088F72E0 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Ok, after going back and forth on this, here is my= untrained analysis of the information I could cull on this subject. On my IO-550N= fuel pressure can be measured both metered and unmetered. Unmetered fuel pres= sure measured between the fuel pump and fuel servo will show pressure supplied to the= engine or fuel pump output. Metered pressure measured from the flow divider will= show pressure wanted by the engine and will vary with throttle position.=

It would seem the interest= here is that the supply pump is working properly, a situation that could be clouded= by the variability in pressure caused by throttle and mixture position if sense= d at the flow divider. A low or high unmetered fuel pressure would indi= cate the engine is not being supplied with enough or too much fuel and this= seems like the more critical information. The gauge port on the flow div= ider for metered fuel pressure seems to be used primarily to drive a pressure typ= e fuel flow gauge not applicable in my case.

I will be re-plumbing to measure unmetered fuel press= ure as this is what Garmin values are set to on the G900 EIS for Continentals= (Garmin measures metered fuel pressure on Lycoming engines). I hope this= makes sense.

Jon Socolof

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