X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Tue, 24 Jun 2014 15:45:50 -0400 Message-ID: X-Original-Return-Path: Received: from mail-yk0-f177.google.com ([209.85.160.177] verified) by logan.com (CommuniGate Pro SMTP 6.0.9e) with ESMTPS id 6947690 for lml@lancaironline.net; Mon, 23 Jun 2014 20:39:10 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.160.177; envelope-from=mwsletten@gmail.com Received: by mail-yk0-f177.google.com with SMTP id 10so5178077ykt.22 for ; Mon, 23 Jun 2014 17:38:35 -0700 (PDT) MIME-Version: 1.0 X-Received: by 10.236.200.228 with SMTP id z64mr9014125yhn.140.1403570315458; Mon, 23 Jun 2014 17:38:35 -0700 (PDT) Received: by 10.170.98.139 with HTTP; Mon, 23 Jun 2014 17:38:35 -0700 (PDT) Received: by 10.170.98.139 with HTTP; Mon, 23 Jun 2014 17:38:35 -0700 (PDT) In-Reply-To: References: X-Original-Date: Mon, 23 Jun 2014 19:38:35 -0500 X-Original-Message-ID: Subject: Re: [LML] Rough idle in Lancair 360 From: Mark Sletten X-Original-To: Lancair Mailing List Content-Type: multipart/alternative; boundary=20cf303f63e811ff3604fc8a2efd --20cf303f63e811ff3604fc8a2efd Content-Type: text/plain; charset=UTF-8 It sounds like you've thoroughly checked out the fuel delivery system. What about the ignition system? Perhaps a bad magneto/plug/plug wire that only manifests when hot? --Mark On Jun 23, 2014 6:27 PM, "Kevin" wrote: > Hello fellow Lacairians, > > I've been dealing with a rough idle problem on a Lycoming IO-360-B1B in a > Lancair 360 for way too long. It only happens when the engine is hot, so > I'm wondering if anyone else has had this problem and what, if anything, > can be done about it. The engine runs very strong in flight, and the > problem only occurs on the ground when hot and at low RPM. Turning on the > boost pump has no effect. The previous owner said he had the same problem > so this has been going on for a very long time. > > After having 4 mechanics look into it and spending thousands of dollars, > the problem remains. So far, we have put on a new fuel servo, new > injectors, new plugs, and checked the timing and ignition system and found > no problems. I've also subscribed to Savvy Analysts and they can't find > anything wrong in the engine data. The next couple of things we are going > to look at (again, but more thoroughly) are both fuel pumps (mechanical and > electrical), and the fuel flow divider. We are also thinking that there > might be an air leak somewhere in the fuel system because the boost pump > won't prime until the engine is cranked on the first start of the day, but > then it boosts just fine. We are also thinking that we could have a vapor > lock problem since it only happens when hot, and these are obviously > tightly-cowled engines. I've heard from other Lancair 360 owners that many > of these planes tend to idle rough when they're hot, so perhaps we've been > chasing our tails this whole time and this is something we just need to > live with? > > One last anomaly that might be worth noting since it has now happened > twice. During climb out on two hot days, fuel pressure began fluctuating > (+/- 5 psi), but then stabilized in level flight at higher airspeeds. Once > again, turning on the boost pump had no effect. Perhaps another indicator > of a possible vapor lock issue? > > Any advice would be greatly appreciated! > > Thanks, > Kevin > > > > -- > For archives and unsub > http://mail.lancaironline.net:81/lists/lml/List.html > --20cf303f63e811ff3604fc8a2efd Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable

It sounds like you've thoroughly checked out the fuel de= livery system. What about the ignition system? Perhaps a bad magneto/plug/p= lug wire that only manifests when hot?

--Mark

On Jun 23, 2014 6:27 PM, "Kevin" <<= a href=3D"mailto:cloudsurfer835@gmail.com">cloudsurfer835@gmail.com>= wrote:

Hello fellow Lacairians,

I've been dealing with a rough idle problem on a Lycoming IO-360-B1B in= a Lancair 360 for way too long. It only happens when the engine is hot, so= I'm wondering if anyone else has had this problem and what, if anythin= g, can be done about it. =C2=A0The engine runs very strong in flight, and t= he problem only occurs on the ground when hot and at low RPM. =C2=A0Turning= on the boost pump has no effect. The previous owner said he had the same p= roblem so this has been going on for a very long time.

After having 4 mechanics look into it and spending thousands of dollars, th= e problem remains. So far, we have put on a new fuel servo, new injectors, = new plugs, and checked the timing and ignition system and found no problems= . I've also subscribed to Savvy Analysts and they can't find anythi= ng wrong in the engine data. The next couple of things we are going to look= at (again, but more thoroughly) are both fuel pumps (mechanical and electr= ical), and the fuel flow divider. We are also thinking that there might be = an air leak somewhere in the fuel system because the boost pump won't p= rime until the engine is cranked on the first start of the day, but then it= boosts just fine. =C2=A0We are also thinking that we could have a vapor lo= ck problem since it only happens when hot, and these are obviously tightly-= cowled engines. I've heard from other Lancair 360 owners that many of t= hese planes tend to idle rough when they're hot, so perhaps we've b= een chasing our tails this whole time and this is something we just need to= live with?

One last anomaly that might be worth noting since it has now happened twice= . During climb out on two hot days, fuel pressure began fluctuating (+/- 5 = psi), but then stabilized in level flight at higher airspeeds. Once again, = turning on the boost pump had no effect. Perhaps another indicator of a pos= sible vapor lock issue?

Any advice would be greatly appreciated!

Thanks,
Kevin

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For archives and unsub http://mail.lancaironline.net:81/lists/lml/L= ist.html

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