Return-Path: Sender: "Marvin Kaye" To: lml@lancaironline.net Date: Tue, 28 Sep 2004 08:24:28 -0400 Message-ID: X-Original-Return-Path: Received: from rwcrmhc11.comcast.net ([204.127.198.35] verified) by logan.com (CommuniGate Pro SMTP 4.2.3) with ESMTP id 435164 for lml@lancaironline.net; Tue, 28 Sep 2004 07:51:09 -0400 Received-SPF: none receiver=logan.com; client-ip=204.127.198.35; envelope-from=mjrav@comcast.net Received: from MJR (h000094c615c2.ne.client2.attbi.com[65.96.140.242]) by comcast.net (rwcrmhc11) with SMTP id <2004092811503701300loguie>; Tue, 28 Sep 2004 11:50:38 +0000 X-Original-Message-ID: <005001c4a552$12800e60$f28c6041@ne2.client2.attbi.com> From: "Mark Ravinski" X-Original-To: "Lancair Mailing List" Subject: LNC2 Vacuum failure and Boost pump problem X-Original-Date: Tue, 28 Sep 2004 07:55:38 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_004D_01C4A530.8AF14F20" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1437 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1441 This is a multi-part message in MIME format. ------=_NextPart_000_004D_01C4A530.8AF14F20 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Ed, Some thaughts on your vaccuum pump. You can stand next to the engine while idling with the cowling off and = do some checking. You can disconnect lines and feel for suction (or = test with another gage). Also you can hear better or even put your = hands on the suspect parts and feel for any vibrations that may = accompany the squealing. Next, take the pump apart. For your boost pump you have two problems. =20 The new pump doesn't work. Mine has a sticker on it for flow direction = but it's wires don't have any polarity. When I had a rough running problem, I did a lot of rework on the fuel = system. (even though the problem turned out to be ignition related.) I did a gascolator drain test like you describe and timed the result. = At gravity feed there was only about five gallons per minute flow. This = is only about one quarter of the engine demand at full power and tells = us that there is a definite suction in the lines between the tank and = first pump. (When the boost pump is off, this suction is present in the = whole system up to the engine driven pump.) I have no filter on this line either. I suggest you remove the filter = or at least put it downstream from the dukes. If you are going to put it downstream, be sure it can handle the pump's = pressure. For this to apply to your priming difficulty, you would have had to have = a very large air leak and a lot of resistance in the filter. =20 I don't expect that moving the pump lower would help at all but check = that all the lines from the tank to the pump slope downward. I would track down that fuel smell if I were you. Look for any trace of = blue staining. I had to repair a small leak in the header tank once. =20 Mark Ravinski N360KB 1304 hrs. ------=_NextPart_000_004D_01C4A530.8AF14F20 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Ed,

Some thaughts on your vaccuum = pump.

You can stand next to the engine while = idling with=20 the cowling off and do some checking. You can disconnect lines and = feel=20 for suction (or test with another gage). Also you can hear better = or=20 even put your hands on the suspect parts and feel for any = vibrations that=20 may accompany the squealing. Next, take the pump = apart.

For your boost pump you have two = problems. =20

The new pump doesn't work. Mine = has a sticker=20 on it for flow direction but it's wires don't have any=20 polarity.

When I had a rough running = problem, I did a=20 lot of rework on the fuel system. (even though the problem turned out to = be=20 ignition related.)

I did a gascolator drain test like you = describe and=20 timed the result. At gravity feed there was only about five = gallons per=20 minute flow. This is only about one quarter of the engine demand = at full=20 power and tells us that there is a definite suction in the lines = between=20 the tank and first pump. (When the boost pump is off, this suction is = present in=20 the whole system up to the engine driven pump.)

I have no filter on this line = either. I=20 suggest you remove the filter or at least put it downstream from the=20 dukes.

If you are going to put it downstream, = be sure it=20 can handle the pump's pressure.

For this to apply to your priming = difficulty, you=20 would have had to have a very large air leak and a lot of resistance in = the=20 filter.

I don't expect that moving the pump = lower would=20 help at all but check that all the lines from the tank to the pump slope = downward.

I would track down that fuel smell if I = were=20 you. Look for any trace of blue staining. I had to repair a = small=20 leak in the header tank once.

Mark Ravinski

N360KB 1304 hrs.

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