X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Mon, 12 Jul 2010 17:53:23 -0400 Message-ID: X-Original-Return-Path: Received: from [69.84.129.240] (HELO asp.reflexion.net) by logan.com (CommuniGate Pro SMTP 5.3.8) with ESMTPS id 4389759 for lml@lancaironline.net; Mon, 12 Jul 2010 10:25:47 -0400 Received-SPF: none receiver=logan.com; client-ip=69.84.129.240; envelope-from=cberland@systems3.net Received: (qmail 21931 invoked from network); 12 Jul 2010 14:25:10 -0000 Received: from unknown (HELO mail-cs-02.app.dcb.reflexion.net) (10.84.19.2) by 0 (rfx-qmail) with SMTP; 12 Jul 2010 14:25:10 -0000 Received: by mail-cs-02.app.dcb.reflexion.net (Reflexion email security v6.20.4) with SMTP; Mon, 12 Jul 2010 10:25:10 -0400 (EDT) Received: (qmail 28648 invoked from network); 12 Jul 2010 14:25:09 -0000 Received: from unknown (HELO remote.systems3.net) (98.172.79.178) by 0 (rfx-qmail) with (AES128-SHA encrypted) SMTP; 12 Jul 2010 14:25:09 -0000 Received: from S3SBS08SERVER.Systems3.local ([fe80::6077:364b:fa39:c71b]) by S3SBS08SERVER.Systems3.local ([fe80::6077:364b:fa39:c71b%10]) with mapi; Mon, 12 Jul 2010 07:25:10 -0700 From: Craig Berland. X-Original-To: Lancair Mailing List X-Original-Date: Mon, 12 Jul 2010 07:25:08 -0700 Subject: [LML] Fuel Control problem Thread-Topic: [LML] Fuel Control problem Thread-Index: Acshx/LBISL6kqp9SyedXXBv94zITAABKMAg X-Original-Message-ID: References: In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: multipart/alternative; boundary="_000_D7A6B5700A0803448C27264F1F5387363FA188A005S3SBS08SERVER_" MIME-Version: 1.0 --_000_D7A6B5700A0803448C27264F1F5387363FA188A005S3SBS08SERVER_ Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable "On High Boost for about 10 seconds, I got about a pint of fuel out the sni= ffle valve. Hmmmmm, it's not supposed to do that." Oh yes it is suppose to do that if you have a newer Continental Engine. Co= ntinental changed the fuel pump design a few years ago and if the engine is= NOT running, the mixture is in full cut off and the boost pump is on......= this will NOT prevent fuel from pouring out of the sniffle valve. This cha= nge made by Continental prevents me from using my standard hot start proced= ure of letting the fuel circulate for 30 seconds while the throttle is wide= open, the mixture in cut off and the high boost on. Now the fuel pours out= on the ground......not good. Craig Berland IV-P On climb out to 14,500' yesterday I was having trouble leaning to 1300 degr= ees. The mixture knob was extra sensitive so I favored the rich side. I= had just topped off with 40 gal. from an above ground tank that was probab= ly around 80 to 85 degrees. Low boost was used from takeoff to about 1500= ' agl., RPM was reduced to 2500 and leaning began. Normally, maintaining= 1300 degrees on the hottest cyl. in the climb (per The Advanced Pilot Cour= se) is easy. (On the previous flight to 15,500' for 2.5 hours I noticed i= t did not lean normally but I was able to go LOP and it held the fuel flow = @ 9.8 gph. No fuel had been added and temp on the ground was about 70 degr= ees.) When we reached 14,500', we accelerated in level off, reduced RPM to 2300 a= nd started to ease the mixture knob back to go Lean of Peak. At 16.5 gal. = per hr., slowly turning the Vernier about 1/8" as normal, fuel flow jumped = to 9 gph. with the engine faltering. I tried this twice before concluding = "this ain't right". I wish I had thought to use Low Boost or to check Fue= l Pressure, but I didn't. We were over the Sierras and headed for the near= est airport but maintained altitude and finally circled down over home base= . I did not mess with the mixture on decent thinking a running engine was= the best option. The control cable, bracket, arm and movement on the mixture are OK. Testin= g for leaks, I had the mixture in idle cut off, throttle open full. With = Low Boost for about 10 seconds, no leaks. On High Boost for about 10 secon= ds, I got about a pint of fuel out the sniffle valve. Hmmmmm, it's not sup= posed to do that. Sounds like the Metering Unit, what do you think? Steve Colwell Legacy IO-550N mostly stock, no ram air or injector mods., = 225 hours tt. --_000_D7A6B5700A0803448C27264F1F5387363FA188A005S3SBS08SERVER_ Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

“On High Boost for about 10 seconds, I got about= a pint of fuel out the sniffle valve.  Hmmmmm, it’s not supposed t= o do that.”

Oh yes it is suppose to = do that if you have a newer Continental Engine.  Continental changed the fuel = pump design a few years ago and if the engine is NOT running, the mixture is in = full cut off and the boost pump is on……this will NOT prevent fuel fr= om pouring out of the sniffle valve.  This change made by Continental prevents me from using my standard hot start procedure of letting the fuel = circulate for 30 seconds while the throttle is wide open, the mixture in cut off and = the high boost on. Now the fuel pours out on the ground……not good.<= o:p>

Craig Berland=

IV-P

 =

On climb out to 14,500’ yesterday I was having t= rouble leaning to 1300 degrees.   The mixture knob was extra sensitive s= o I favored the rich side.   I had just topped off with 40 gal. from = an above ground tank that was probably around 80 to 85 degrees.   Lo= w boost was used from takeoff to about 1500’ agl.,  RPM was reduce= d to 2500 and leaning began.   Normally, maintaining 1300 degrees on t= he hottest cyl. in the climb (per The Advanced Pilot Course) is easy.   (On the previous flight to 15,500’ for 2.5 hours I noticed it d= id not lean normally but I was able to go LOP and it held the fuel flow @ 9.8 gph.  No fuel had been added and temp on the ground was about 70 degre= es.)

 

When we reached 14,500’, we accelerated in level= off, reduced RPM to 2300 and started to ease the mixture knob back to go Lean of Peak.&n= bsp; At 16.5 gal. per hr., slowly turning the Vernier about 1/8” as normal= , fuel flow jumped to 9 gph. with the engine faltering.  I tried this tw= ice before concluding “this ain’t right”.   I wish = I had thought to use Low Boost or to check Fuel Pressure, but I didn’t.  We were over the Sierras and headed for the nearest air= port but maintained altitude and finally circled down over home base.  &nbs= p;I did not mess with the mixture on decent thinking a running engine was the b= est option. 

 

The control cable, bracket, arm and movement on the mi= xture are OK.  Testing for leaks, I had the mixture in idle cut off, throttl= e open full.   With Low Boost for about 10 seconds, no leaks. = On High Boost for about 10 seconds, I got about a pint of fuel out the sniffle valve.  Hmmmmm, it’s not supposed to do that.  <= /p>

 

Sounds like the Metering Unit, what do you think?=

 

Steve Colwell   Legacy IO-550N mostly stock,= no ram air or injector mods., 225 hours tt.

 

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