X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fmailhost05.isp.att.net ([207.115.11.55] verified) by logan.com (CommuniGate Pro SMTP 5.3.6) with ESMTP id 4247349 for flyrotary@lancaironline.net; Tue, 04 May 2010 13:20:20 -0400 Received-SPF: none receiver=logan.com; client-ip=207.115.11.55; envelope-from=bbradburry@bellsouth.net Received: from desktop (adsl-85-113-131.mco.bellsouth.net[98.85.113.131]) by isp.att.net (frfwmhc05) with SMTP id <20100504171945H0500rrsoge>; Tue, 4 May 2010 17:19:45 +0000 X-Originating-IP: [98.85.113.131] From: "Bill Bradburry" To: "'Rotary motors in aircraft'" References: In-Reply-To: Subject: RE: [FlyRotary] Re: tuning issues Date: Tue, 4 May 2010 13:19:53 -0400 Message-ID: <8AA5EDC3BA7748F8BDB1756DAEE80913@Desktop> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0009_01CAEB8C.7BD8E040" X-Mailer: Microsoft Office Outlook 11 Thread-Index: AcrrqlScyT//r8KGRnq0+32Vxr8pSAAAzU5A X-MimeOLE: Produced By Microsoft MimeOLE V6.0.6001.18049 This is a multi-part message in MIME format. ------=_NextPart_000_0009_01CAEB8C.7BD8E040 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit I don't think it is fuel filter related. The fuel pressure is holding steady during this time. I think it is some kind of misfire, but have no clue as to what could be causing it or how to go about diagnosing it. It is both random and intermittent and happens at various rpms. Nothing seems consistant about it happening. What should I check? Bill B _____ From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Tracy Crook Sent: Tuesday, May 04, 2010 12:53 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: tuning issues Anything that causes a misfire will cause the mixture to indicate lean. Remember, it's an Oxygen sensor. If you don't burn the fuel it's got a lot of that being pumped down the exhaust making the instrument think things are Very lean.. Problem may not be fuel related at all. Tracy On Tue, May 4, 2010 at 11:46 AM, Bill Bradburry wrote: After I get the engine running smoothly in a range, it will occasionally hiccup. When it does, the mixture will then go down sometimes off the scale, then come back to where it was. I have not noticed any dips in the MAP table at these locations. Any ideas, suggestions? Bill B -- Homepage: http://www.flyrotary.com/ Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.html ------=_NextPart_000_0009_01CAEB8C.7BD8E040 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

I don’t think it is fuel = filter related.  The fuel pressure is holding steady during this = time.  I think it is some kind of misfire, but have no clue as to what could be causing it or = how to go about diagnosing it.  It is both random and intermittent and = happens at various rpms.  Nothing seems consistant about it = happening.

What should I = check?

 

Bill B

 

From: = Rotary motors in aircraft = [mailto:flyrotary@lancaironline.net] On Behalf Of Tracy = Crook
Sent: Tuesday, May 04, = 2010 12:53 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: = tuning issues

 

Anything that = causes a misfire will cause the mixture to indicate lean.  Remember, it's an = Oxygen sensor.  If you don't burn the fuel it's got a lot of that being = pumped down the exhaust  making the instrument think things are Very = lean.. 

Problem may not be fuel related at all.

Tracy

On Tue, May 4, 2010 at 11:46 AM, Bill Bradburry <bbradburry@bellsouth.net>= wrote:

After I get the engine running smoothly in a range, it will occasionally
hiccup.  When it does, the mixture will then go down sometimes off = the
scale, then come back to where it was.  I have not noticed any dips = in the
MAP table at these locations.
Any ideas, suggestions?

Bill B

 

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