X-CGP-ClamAV-Result: CLEAN X-VirusScanner: Niversoft's CGPClamav Helper v1.23.0 (ClamAV engine v0.103.0) X-Junk-Score: 0 [] X-KAS-Score: 0 [] From: "David COOK hoursaway1@comcast.net" Received: from resqmta-h1p-028593.sys.comcast.net ([96.102.200.7] verified) by logan.com (CommuniGate Pro SMTP 6.3.11) with ESMTPS id 1015965 for flyrotary@lancaironline.net; Sun, 22 May 2022 22:49:25 -0400 Received-SPF: pass receiver=logan.com; client-ip=96.102.200.7; envelope-from=hoursaway1@comcast.net Received: from resomta-h1p-028516.sys.comcast.net ([96.102.179.207]) by resqmta-h1p-028593.sys.comcast.net with ESMTP id sy3TnknisKHXIsy84n5Lcv; Mon, 23 May 2022 02:49:08 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=comcast.net; s=20190202a; t=1653274148; bh=sBNRp/GFyGJcy3T/GM3nasdVGNr+4auwrWX2M+tE6nQ=; h=Received:Received:Date:From:To:Message-ID:Subject:MIME-Version: Content-Type; b=RG9XnW4fUfPjxTYYwpILsqG+t4U3oskyYJbVXr4B4j52Xd4XzdZ4e9bGrmU5CGLg8 KqAZPlnWSaSyKp+mROLqLBU1IE/lVJfPrrcs904yY+LsA/y1iqyZ6ysCfSzihtqrrT DrhzEnUi1O7C3BcMohygA1x2hBeGngEmtyc7qvYShiMRIvwUX3CEfkC2m1vsCIjJsO BEjti/OEp04Rd4sKI742QYCNM0eQJU9Iri/dsj/hmcpto2QaLqEahX/I5B+SAgSe26 w8A/6QHVCiI3AighY24V1FpdVB3l5fKAy/97LAshQHkmjEgQz5x9ZDSsY5j01SGRY9 P0ZsKmlAO8qWg== Received: from oxapp-ch2g-05o.email.comcast.net ([96.118.129.187]) by resomta-h1p-028516.sys.comcast.net with ESMTPS id sy82n6Uk1vwWwsy83nwBEo; Mon, 23 May 2022 02:49:07 +0000 X-Xfinity-VAAS: gggruggvucftvghtrhhoucdtuddrgedvfedrieelgdeivdcutefuodetggdotefrodftvfcurfhrohhfihhlvgemucevohhmtggrshhtqdftvghsihdpqfgfvfdppffquffrtefokffrnecuuegrihhlohhuthemuceftddunecunecujfgurhepfffhvffkjghfufggtgfrkgfoihesrgdtsggsredtjeenucfhrhhomhepffgrvhhiugcuvefqqffmuceohhhouhhrshgrfigrhidusegtohhmtggrshhtrdhnvghtqeenucggtffrrghtthgvrhhnpeeludeifeelueekfeelgfegjedujefhieeuhfelkeefveejteefteeiteeuledvgeenucfkphepleeirdduudekrdduvdelrddukeejpdduieehrddvvdehrdehledrkeenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhephhgvlhhopehogigrphhpqdgthhdvghdqtdehohdrvghmrghilhdrtghomhgtrghsthdrnhgvthdpihhnvghtpeeliedruddukedruddvledrudekjedpmhgrihhlfhhrohhmpehhohhurhhsrgifrgihudestghomhgtrghsthdrnhgvthdpnhgspghrtghpthhtohepuddprhgtphhtthhopehflhihrhhothgrrhihsehlrghntggrihhrohhnlhhinhgvrdhnvght X-Xfinity-VMeta: sc=0.00;st=legit Date: Sun, 22 May 2022 22:49:06 -0400 (EDT) To: Rotary motors in aircraft Message-ID: <1031699874.157863.1653274146810@connect.xfinity.com> In-Reply-To: References: Subject: Re: [FlyRotary] Re: Fuel pressure trending lower. MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_157862_38241800.1653274146794" X-Priority: 3 Importance: Normal X-Mailer: Open-Xchange Mailer v7.10.5-Rev21 X-Originating-IP: ::ffff:165.225.59.8 X-Originating-Client: open-xchange-appsuite ------=_Part_157862_38241800.1653274146794 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Hey Fin, quick thought, how about air on the low pres. in-side of the pump = via leaky fitting ect. ? Draws air in during op. but not leaking enough t= o find or show witness marks when static ? David R. Cook RV6A Rotary > On 05/22/2022 8:44 PM Finn Lassen finn.lassen@verizon.net wrote: >=20 >=20 > Thanks Steve. >=20 > From your March/April 2017 posts it was a GSL392 that failed (high cu= rrent draw/low pressure, even after you removed the insect you found in the= inlet). >=20 > So this afternoon I ran the pump for about an hour. Amp draw from 3.0= 4 to 2.86 depending on voltage. Pressure between 43 and 40 psi (also depend= ing on voltage). No noticeable degradation. Of course the difference with t= his test is that no fuel went to engine -- all recirculated through pressur= e regulator and back to tank. But no signs of a failing pump in terms of hi= gher current draw and less pressure. >=20 > I guess I should put a temp probe on the pump and see what it reads d= uring flight to see if that could be a factor. >=20 > Finn >=20 > On 5/21/2022 9:01 PM, Stephen Izett stephen.izett@gmail.com mailto:st= ephen.izett@gmail.com wrote: >=20 > > > Hi Finn > >=20 > > I had from memory a 393 fail. Can=E2=80=99t recall the symptoms= sorry. > >=20 > > I test before takeoff and then run both pumps below 2ooo ft inc= ase of failure. > > I plan to instal a comparator relay board in fuel pressure circ= uit to automatically bring on backup pump and failure indicator. > > So testing before flight becomes - switch off and back on main = engine pump. This will save amps and wear of backup pump. > > When I switch off a pump at WOT the engine dies pretty much ins= tantaneously and don't want to be fiddling with a restart in the Glasair wh= ich glides like a brick with the gear out in the breeze. > >=20 > > Regards =20 > > Steve Izett > >=20 > >=20 > >=20 > >=20 > >=20 > >=20 > > > > > On 21 May 2022, at 10:30 pm, Finn Lassen = finn.lassen@verizon.net mailto:finn.lassen@verizon.net wrote: > > >=20 > > > Recently I noticed my fuel pressure being low. Noticed be= cause engine did not come up in power when advancing to full throttle. Noti= ced mixture real lean. Checking fuel pressure as low as 28 psi (normally 35= and up to 40 at full throttle). > > >=20 > > > Going over my engine logs since first flight I now see th= at fuel pressure has been trending lower through each flight -- more pronou= nced on longer flights (40+ minutes). More and more pronounced over the mon= ths and became really noticeable over last month. Could explain why mixture= tuning appeared to have changed. Nice to have engine logs from practically= each flight. > > >=20 > > > But why? Pump getting weaker? > > >=20 > > > My primary fuel pump is a GSL414. I figured it was wasted= energy to push way more fuel than needed through the pressure regulator ba= ck to the tank. > > >=20 > > > My secondary (backup) pump is a GSL393. When turning that= on, fuel pressure comes back up to where it needs to be. > > >=20 > > > Anyone have experience with failing or weak EFI pumps, pa= rticularly the GSL414? > > >=20 > > > Finn > > >=20 > > > > >=20 > >=20 > > >=20 >=20 ------=_Part_157862_38241800.1653274146794 MIME-Version: 1.0 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable =20 =20
Hey Fin, quick thought, how about air on the low pres. in-side of = the pump via leaky fitting ect. ?   Draws air in during op. but n= ot leaking enough to find or show witness marks when static ?   D= avid R. Cook RV6A Rotary
On 05/22/2022 8:44 PM Finn Lassen finn.lassen@verizon.net <flyrotary= @lancaironline.net> wrote:


Thanks Steve.

From your March/April 2017 posts it was a GSL392 that failed (high = current draw/low pressure, even after you removed the insect you found in t= he inlet).

So this afternoon I ran the pump for about an hour. Amp draw from 3= .04 to 2.86 depending on voltage. Pressure between 43 and 40 psi (also depe= nding on voltage). No noticeable degradation. Of course the difference with= this test is that no fuel went to engine -- all recirculated through press= ure regulator and back to tank. But no signs of a failing pump in terms of = higher current draw and less pressure.

I guess I should put a temp probe on the pump and see what it reads= during flight to see if that could be a factor.

Finn

On 5/21/2022 9:01 PM, Stephen Izett stephen.izett@gmail.com = wrote:
Hi Finn

I had from memory a 393 fail. Can=E2=80=99t recall the symptoms sorry.

I test before takeoff and then run both pumps below 2ooo ft incase of = failure.
I plan to instal a comparator relay board in fuel pressure circuit to = automatically bring on backup pump and failure indicator.
So testing before flight becomes - switch off and back on main engine = pump. This will save amps and wear of backup pump.
When I switch off a pump at WOT the engine dies pretty much instantane= ously and don't want to be fiddling with a restart in the Glasair which gli= des like a brick with the gear out in the breeze.

Regards  
Steve Izett





On 21 May 2022, at 10:30 pm, Finn Lassen finn.lassen@verizon.net <flyrotary@lancaironline.net&= gt; wrote:

Recently I noticed my fuel pressure being low. Notic= ed because engine did not come up in power when advancing to full throttle.= Noticed mixture real lean. Checking fuel pressure as low as 28 psi (normal= ly 35 and up to 40 at full throttle).

Going over my engine logs since first flight I now s= ee that fuel pressure has been trending lower through each flight -- more p= ronounced on longer flights (40+ minutes). More and more pronounced over th= e months and became really noticeable over last month. Could explain why mi= xture tuning appeared to have changed. Nice to have eng= ine logs from practically each flight.

But why= ? Pump getting weaker?

My primary fuel pump is a GSL414. I figured it was w= asted energy to push way more fuel than needed through the pressure regulat= or back to the tank.

My secondary (backup) pump is a GSL393. When turning= that on, fuel pressure comes back up to where it needs to be.

Anyone have experience with failing or weak EFI pump= s, particularly the GSL414?

Finn



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