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: " 12348ung@gmail.com" Received: from mail-pg1-f176.google.com ([209.85.215.176] verified) by logan.com (CommuniGate Pro SMTP 6.3.11) with ESMTPS id 1013194 for flyrotary@lancaironline.net; Sat, 21 May 2022 19:09:17 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.215.176; envelope-from=12348ung@gmail.com Received: by mail-pg1-f176.google.com with SMTP id a38so7766997pgl.9 for ; Sat, 21 May 2022 16:09:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:references:in-reply-to:subject:date:message-id:mime-version :thread-index:content-language; bh=AM6g9T6zlpEDgi/cyEEIVWCYfLSyXiYNpEWF4ayhID4=; b=eOwtjPnqDmmv5/7qe2oaSqC6UgynPdBAjg5RPPpVw/ZDBSgLrbmPaF0nRXro5H+C1w ETrVssW1doysIM31NNyBWufatmkgGHnW0lQ6KwwlyFIpgRSL10vwf4Uu090aig5jdhy2 a3gSFEO+q4rinI+8D0C8xbFV02+ktVlpZmRSumP3X+EDQ03CaU4g6DHNp/HyA+F4evj5 9mwWm9QNNW4Ti6hsOsP8yWagaLV4AOhZgINPSI5oa/YQvyakxyCDczchzZaF6Gm4C3VQ 6JgpcIFG98ZhCoRs7judkpzwrOPfYZcDZDgZ/KHcGcunaUoJWLrn4X868Y8qaHjibdzX yvPg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:references:in-reply-to:subject:date :message-id:mime-version:thread-index:content-language; bh=AM6g9T6zlpEDgi/cyEEIVWCYfLSyXiYNpEWF4ayhID4=; b=P3pBK4JJecEOBN9fhR5AQEjx1fDEfS4c5cYDf0r6yQev99jSTRSrg5lGrZE7rZislc +i0RpUHp0LfAlskhLbRuEgiLH45XCoJEpbczRFFrfIWdo7lUALAHVK+CUqjz2m07Xo2F AJVFA62q6lY8mntnYcqkXPIkwnPcl1f0yTlervMYD2gkCWeTKGYSV6HnpeE8r4cxq0oK YiAwSS4OEqSg28qkHInrJVNcH00c38mWa6rlotr2jW3ZNbhDSZwb6VZd6Xkago2//aKJ FTbqNriB4l65h0sqDimRGSYhMBTiFaL/wzCe9gXitF6mGM9qHcYz0nYKojm8Ja8UcBul 1WtQ== X-Gm-Message-State: AOAM532kZlydjty5n+Nezc+MvlfBF640vMJYfBSdW/ubsqz1egYbQ/hf WntUyDl/2IWRvz8y/cH2ykASdr/9/SI= X-Google-Smtp-Source: ABdhPJx+UjR2IvyZDKvEO4oVpmKU74xGoCU9Evvjh9/0KLD/w+OM0tbf70pHS1Y0mYM+lFHVddJtjg== X-Received: by 2002:a63:455e:0:b0:3c6:270f:cec4 with SMTP id u30-20020a63455e000000b003c6270fcec4mr14063690pgk.417.1653174540078; Sat, 21 May 2022 16:09:00 -0700 (PDT) Return-Path: <12348ung@gmail.com> Received: from UserPC ([103.198.24.78]) by smtp.gmail.com with ESMTPSA id i13-20020a056a00224d00b00518382bceaesm4211044pfu.57.2022.05.21.16.08.58 for (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Sat, 21 May 2022 16:08:59 -0700 (PDT) To: "'Rotary motors in aircraft'" References: In-Reply-To: Subject: RE: [FlyRotary] Re: Fuel pressure trending lower. Date: Sun, 22 May 2022 09:08:56 +1000 Message-ID: <001701d86d67$c0c0f5c0$4242e140$@gmail.com> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0018_01D86DBB.926F4FB0" X-Mailer: Microsoft Outlook 16.0 Thread-Index: AQJB4Vw19cgmfadN2fJKQt1LIUxJJqxXC1gA Content-Language: en-us This is a multipart message in MIME format. ------=_NextPart_000_0018_01D86DBB.926F4FB0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Finn, Always the way with =E2=80=9Cdiagnostics=E2=80=9D. You = will not know until it is fixed. If pressure is ok with both pumps = going through the same filter? Then filters suggest are OK. Main pump = could be explained in that performance is marginal even when cold but = when heated expands radially and efficiency drops just that fraction. AS I said impossible to verify unless replaced. Neil. =20 =20 From: Rotary motors in aircraft =20 Sent: Sunday, May 22, 2022 8:21 AM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Fuel pressure trending lower. =20 After maybe less than 75 hours in use? Recently, during annual, I discovered I'd installed the pre-pumps filter = the wrong way. Tried to clean the cartridge real well, but not = impossible that some junk hidden under the edges could have gotten into = the main pump input as I'm only running the backup pump for a few = seconds during pre-flight checks. Actually that doesn't explain the long = term decline. So back to the pump failing. Dang! But why full pressure = when cold and then gradually dropping during flight (dropping more = recently). It's my understanding that the Walbro EFI pumps do not have check valves = but acts as a valve when turned off. Thus no fuel off-valve in my RV-4. Now I'm wondering if this is happening to others but just not visible = when using the higher capacity GSL393, 392 or 391 pumps. They would have = to degrade to below the fuel regulator setting before becoming = noticeable. For some reason the GSL393 is cheaper than the GSL414.=20 Finn =20 On 5/21/2022 5:58 PM, 12348ung@gmail.com = wrote: Finn, Once again the blind leading the blind, but it appears that = wear and old age has gotten to your pump. I suspect that as with the = second pump all is normal, then that excludes filter and water etc, just = needs a replacement pump IMHO. Easy when it is your money! Neil. =20 =20 From: Rotary motors in aircraft = =20 Sent: Sunday, May 22, 2022 2:14 AM To: Rotary motors in aircraft = Subject: [FlyRotary] Re: Fuel pressure trending lower. =20 Do EFI pumps have an internal check valve? Dirty fuel filter? =20 =20 Bobby =20 Get Outlook for iOS =20 _____ =20 From: Rotary motors in aircraft > on behalf of Finn Lassen = finn.lassen@verizon.net = > Sent: Saturday, May 21, 2022 9:30:30 AM To: Rotary motors in aircraft > Subject: [FlyRotary] Fuel pressure trending lower.=20 =20 Recently I noticed my fuel pressure being low. Noticed 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 (normally 35 = and up to 40 at full throttle). Going over my engine logs since first flight I now see that fuel = pressure has been trending lower through each flight -- more pronounced = on longer flights (40+ minutes). More and more pronounced over the = months 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. But why? Pump getting weaker? My primary fuel pump is a GSL414. I figured it was wasted energy to push = way more fuel than needed through the pressure regulator 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 pumps, particularly the = GSL414? Finn =20 Disclaimer The information contained in this communication from the sender is = confidential. It is intended solely for use by the recipient and others = authorized to receive it. If you are not the recipient, you are hereby = notified that any disclosure, copying, distribution or taking action in = relation of the contents of this information is strictly prohibited and = may be unlawful. This email has been scanned for viruses and malware, and may have been = automatically archived by Mimecast Ltd, an innovator in Software as a = Service (SaaS) for business. Providing a safer and more useful place for = your human generated data. Specializing in; Security, archiving and = compliance. To find out more Click = Here =20 ------=_NextPart_000_0018_01D86DBB.926F4FB0 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable

Finn,

=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 Always the way with = =E2=80=9Cdiagnostics=E2=80=9D.=C2=A0 You will not know until it is = fixed. =C2=A0=C2=A0If pressure is ok with both pumps going through the = same filter? Then filters suggest are OK.=C2=A0=C2=A0 Main pump could be = explained in that performance is marginal even when cold but when heated = expands radially and efficiency drops just that = fraction.

AS I said impossible to verify unless = replaced.

Neil. =C2=A0

 

From: Rotary motors in aircraft = <flyrotary@lancaironline.net>
Sent: Sunday, May 22, = 2022 8:21 AM
To: Rotary motors in aircraft = <flyrotary@lancaironline.net>
Subject: [FlyRotary] Re: = Fuel pressure trending lower.

 

After = maybe less than 75 hours in use?

Recently, during annual, I = discovered I'd installed the pre-pumps filter the wrong way. Tried to = clean the cartridge real well, but not impossible that some junk hidden = under the edges could have gotten into the main pump input as I'm only = running the backup pump for a few seconds during pre-flight checks. = Actually that doesn't explain the long term decline. So back to the pump = failing. Dang! But why full pressure when cold and then gradually = dropping during flight (dropping more recently).

It's my = understanding that the Walbro EFI pumps do not have check valves but = acts as a valve when turned off. Thus no fuel off-valve in my = RV-4.

Now I'm wondering if this is happening to others but just = not visible when using the higher capacity GSL393, 392 or 391 pumps. = They would have to degrade to below the fuel regulator setting before = becoming noticeable.

For some reason the GSL393 is cheaper than = the GSL414.

Finn
 
On 5/21/2022 5:58 PM, 12348ung@gmail.com = wrote:

Finn,

          =   Once again the blind leading the blind, but it appears that wear = and old age has gotten to your pump.  I suspect that as with the = second pump all is normal, then that excludes filter and water etc, just = needs a replacement pump IMHO.

          =       Easy when it is your = money!

Neil.

          =   

 

From: Rotary motors in aircraft <flyrotary@lancaironline.n= et>
Sent: Sunday, May 22, 2022 2:14 AM
To: = Rotary motors in aircraft <flyrotary@lancaironline.n= et>
Subject: [FlyRotary] Re: Fuel pressure trending = lower.

 

Do EFI pumps have an internal check valve? Dirty fuel = filter?  

 

Bobby

Recently I noticed my fuel pressure being = low. Noticed 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 (normally 35 and up to 40 at full throttle).

Going over my engine logs since first flight = I now see that fuel pressure has been trending lower through each flight = -- more pronounced on longer flights (40+ minutes). More and more = pronounced over the months 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.

But why? Pump = getting weaker?

My primary = fuel pump is a GSL414. I figured it was wasted energy to push way more = fuel than needed through the pressure regulator 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 pumps, particularly the = GSL414?

Finn

 

Disclaimer

= The information contained in this communication from the sender is = confidential. It is intended solely for use by the recipient and others = authorized to receive it. If you are not the recipient, you are hereby = notified that any disclosure, copying, distribution or taking action in = relation of the contents of this information is strictly prohibited and = may be unlawful.

This email has been scanned for viruses and = malware, and may have been automatically archived by Mimecast = Ltd, an innovator in Software as a Service (SaaS) for business. = Providing a safer and more useful place for your human = generated data. Specializing in; Security, archiving and compliance. To = find out more Click = Here

 

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