X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Tue, 24 Jun 2014 15:46:47 -0400 Message-ID: X-Original-Return-Path: Received: from nm15-vm6.bullet.mail.gq1.yahoo.com ([98.137.176.78] verified) by logan.com (CommuniGate Pro SMTP 6.0.9e) with ESMTPS id 6948021 for lml@lancaironline.net; Tue, 24 Jun 2014 06:45:52 -0400 Received-SPF: pass receiver=logan.com; client-ip=98.137.176.78; envelope-from=casey.gary@yahoo.com Received: from [98.137.12.63] by nm15.bullet.mail.gq1.yahoo.com with NNFMP; 24 Jun 2014 10:45:16 -0000 Received: from [216.39.60.204] by tm8.bullet.mail.gq1.yahoo.com with NNFMP; 24 Jun 2014 10:45:16 -0000 Received: from [127.0.0.1] by omp1091.mail.gq1.yahoo.com with NNFMP; 24 Jun 2014 10:45:16 -0000 X-Yahoo-Newman-Property: ymail-3 X-Yahoo-Newman-Id: 145057.17980.bm@omp1091.mail.gq1.yahoo.com Received: (qmail 55673 invoked by uid 60001); 24 Jun 2014 10:45:16 -0000 X-YMail-OSG: U7sQ91EVM1mYTdAlIGf6zrXKosI8A4K0HKsa5MF5j3Od_uI ArBnqWOddFQN8Fvsva4sad.KRQwWSP9hOlPDQ7_1M622iZOuq8Z6nGWPHD.m bRRc_5jxBDEy_TNzvc7PFdevsFIaWtJb3l1U0iQg1DX.qPtXH.6QjuleB38v BUhWcVNOysNoQvZsbWp7_wi2uRusKnGVX6D6Gi6FBCO5mjIaeI8h3RB0OXES OyYPON5WYY3a0britEnm_oddtNyLmsHQyI7vPnFTh05WWoL2pUj6n2ngDOzr tm.xWpS1mX_yKn6lxkI2dwHDuJaVKP_HPcgTqc281h80kogwD3IA9JLXJt6p qV6DLuCghcMGoTCbuWmAquQC.DdjzQ3Fd7KySbVMUIkIIP33okd73TtoZ5rO CYCEBQx_8nLmcQb4lW5za0RRTNUX6Ddta6jdD2QiLp1FtGdlbvdck.CeQxwV 6Vq7LhOmJ2xLv3tzDNB1zKcoNEQUNTXtpYPIM_IB8.dP402RyJNbHKeEyyZy l3CROqsD6.ixaFna2joW4WUY9n7IBSQKMx4PLp3FrkzYA88So2IOEBqlA5Q- - Received: from [24.247.14.116] by web163503.mail.gq1.yahoo.com via HTTP; Tue, 24 Jun 2014 03:45:15 PDT X-Rocket-MIMEInfo: 002.001,SSBhZ3JlZSB0aGF0IGhlYXQgaXMgdGhlIG9idmlvdXMgY3VscHJpdCwgYnV0IGl0IHNvdW5kcyBsaWtlIHRoZSBwcm9ibGVtIGlzbid0IHRoZSBlbmdpbmUtbW91bnRlZCBmdWVsIHB1bXAgdmFwb3ItbG9ja2luZy4gwqBJZiB0aGUgZWxlY3RyaWMgcHVtcCBoYXMgbm8gZWZmZWN0LCB0aGUgcHJvYmxlbSBwcm9iYWJseSBpc24ndCBiZXR3ZWVuIHRoZSB0YW5rIGFuZCBmdWVsIHNlcnZvLiDCoElzIHRoZSBsaW5lIGZyb20gdGhlIHNlcnZvIHRvIHRoZSBkaXN0cmlidXRvciB3ZWxsIGluc3VsYXRlZD8gwqBJIGwBMAEBAQE- X-Mailer: YahooMailWebService/0.8.191.1 References: X-Original-Message-ID: <1403606715.42678.YahooMailNeo@web163503.mail.gq1.yahoo.com> X-Original-Date: Tue, 24 Jun 2014 03:45:15 -0700 From: Gary Casey Reply-To: Gary Casey Subject: Re: Rough idle in Lancair 360 X-Original-To: Lancair Mailing List In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="48240482-1532223306-1403606715=:42678" --48240482-1532223306-1403606715=:42678 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable I agree that heat is the obvious culprit, but it sounds like the problem is= n't the engine-mounted fuel pump vapor-locking. =A0If the electric pump has= no effect, the problem probably isn't between the tank and fuel servo. =A0= Is the line from the servo to the distributor well insulated? =A0I like to = use the old-fashioned loose-fitting fire sleeve for this as it offers good = insulation. =A0The next thing is to make sure all components are as cool as= possible. =A0There should be a shroud around the fuel pump with cool air d= ucted to it. =A0The gascolator should be isolated from the engine compartme= nt and cooled. =A0Yes, there is a remote possibility of an air leak causing= a problem. =A0Sometimes air will leak in, but fuel won't leak out. =A0And = sometimes electric pumps are located higher than they could be or are in th= e engine compartment and therefore run hotter than they should. =A0In order= , I would:=0A1. =A0Insulate all fuel lines with fire sleeve.=0A2. =A0Duct c= ool air to the mechanical pump=0A3. =A0Duct cool air to the gascolator.=0A4= . =A0Think about relocating the electric pump=0A5. =A0Look for an air leak= =0A=0AGary Casey=0AHello fellow Lacairians,=0A=0AI've been dealing with a r= ough idle problem on a Lycoming IO-360-B1B in a La=3D=0Ancair 360 for way t= oo long. It only happens when the engine is hot, so I'm w=3D=0Aondering if = anyone else has had this problem and what, if anything, can be d=3D=0Aone a= bout it.=A0 The engine runs very strong in flight, and the problem only o= =3D=0Accurs on the ground when hot and at low RPM.=A0 Turning on the boost = pump has n=3D=0Ao effect. The previous owner said he had the same problem s= o this has been g=3D=0Aoing on for a very long time.=3D20=0A=0AAfter having= 4 mechanics look into it and spending thousands of dollars, the=3D=0Aprobl= em remains. So far, we have put on a new fuel servo, new injectors, ne=3D= =0Aw plugs, and checked the timing and ignition system and found no problem= s. I=3D=0A've also subscribed to Savvy Analysts and they can't find anythin= g wrong in t=3D=0Ahe engine data. The next couple of things we are going to= look at (again, bu=3D=0At more thoroughly) are both fuel pumps (mechanical= and electrical), and the f=3D=0Auel flow divider. We are also thinking tha= t there might be an air leak somew=3D=0Ahere in the fuel system because the= boost pump won't prime until the engine i=3D=0As cranked on the first star= t of the day, but then it boosts just fine.=A0 We a=3D=0Are also thinking t= hat we could have a vapor lock problem since it only happe=3D=0Ans when hot= , and these are obviously tightly-cowled engines. I've heard from=3D=0Aothe= r Lancair 360 owners that many of these planes tend to idle rough when t=3D= =0Ahey're hot, so perhaps we've been chasing our tails this whole time and = this=3D=0Ais something we just need to live with?=0A=0AOne last anomaly tha= t might be worth noting since it has now happened twice.=3D=0ADuring climb = out on two hot days, fuel pressure began fluctuating (+/- 5 ps=3D=0Ai), but= then stabilized in level flight at higher airspeeds. Once again, tur=3D=0A= ning on the boost pump had no effect. Perhaps another indicator of a possib= l=3D=0Ae vapor lock issue? =3D20=0A=0AAny advice would be greatly appreciat= ed!=0A=0AThanks,=0AKevin --48240482-1532223306-1403606715=:42678 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable
I agree that heat is the obvious culprit, but it sounds = like the problem isn't the engine-mounted fuel pump vapor-locking.  If= the electric pump has no effect, the problem probably isn't between the ta= nk and fuel servo.  Is the line from the servo to the distributor well= insulated?  I like to use the old-fashioned loose-fitting fire sleeve= for this as it offers good insulation.  The next thing is to make sur= e all components are as cool as possible.  There should be a shroud ar= ound the fuel pump with cool air ducted to it.  The gascolator should be i= solated from the engine compartment and cooled.  Yes, there is a remot= e possibility of an air leak causing a problem.  Sometimes air will le= ak in, but fuel won't leak out.  And sometimes electric pumps are loca= ted higher than they could be or are in the engine compartment and therefor= e run hotter than they should.  In order, I would:
1.  Insulate all fuel lines with fire sleeve.
2. =  Duct cool air to the mechanical pump
3.  Duc= t cool air to the gascolator.
4.  Think about relo= cating the electric pump
5.  Look for an air leak

Gary Casey
Hello fellow Lacairians,

I've been dealing wit= h a rough idle problem on a Lycoming IO-360-B1B in a=0A La=3D
ncair 360 for way t= oo long. It only happens when the engine is hot, so I'm w=3D
ondering if anyone e= lse has had this problem and what, if anything, can be d=3D
one about it.  T= he engine runs very strong in flight, and the problem only o=3D
<= span style=3D"font-family: monospace; font-size: 13px;" class=3D"yiv8483512857"= >ccurs on the ground when hot and at low RPM.  Turning on the boost pu= mp has=0A n=3D
o effect. The previous owner said he had the= same problem so this has been g=3D
oing on for a very long= time.=3D20

After having 4 mechanics look into it and s= pending thousands of dollars, the=3D
problem remains. So fa= r, we have put on a new fuel servo, new injectors, ne=3D
w plugs, and checked the timing and ignit= ion system and found no problems. I=3D
've also subscribed = to Savvy Analysts and they can't find anything wrong in t=3D
he engine data. The next couple of things we are going to look at (again,= bu=3D
t more thoroughly) are both fuel pumps (mechanical and electrical), and the f=3D
uel flow d= ivider. We are also thinking that there might be=0A an air leak somew=3D
here in the fuel system because the boost pump won't prime un= til the engine i=3D
s cranked on the first start of the day, but then it boosts j= ust fine.  We a=3D
re also thinking that we could have= a vapor lock problem since it only happe=3D
ns when hot, and thes= e are obviously tightly-cowled engines. I've heard from=3D
other Lancair 360 owners that many of these planes tend to idle rough when= t=3D
hey're hot, so perhaps we've been chasing our tails t= his whole time and this=3D
is something we just need to liv= e with?

One last anomaly that might be worth noting since it has now happened twic= e.=3D
During climb out on two hot days, fuel pressure began= fluctuating (+/- 5 ps=3D
i), but then stabilized in level = flight at higher airspeeds. Once again, tur=3D
ning on the = boost pump had no effect. Perhaps another indicator of a possibl=3D<= br style=3D"font-family: monospace; font-size: 13px;" class=3D"yiv848351285= 7">e vapor lock issue? = =3D20

Any advice would be greatly appreciated!
Thanks,
Kevin

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