Date: Tue, 12 May 2009 07:57:17 -0400
Reply-To: Ken Wilford <kenwilfy@COMCAST.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Ken Wilford <kenwilfy@COMCAST.NET>
Subject: Re: Digifant Fuel System Troubleshooting Experience
In-Reply-To: <581958.48152.qm@web33502.mail.mud.yahoo.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Robert it is to keep you from burning to death in case of an accident.
The van crashes, a fuel line ruptures, and because of a jimmy rig repair
gas is constantly pumping out of a ruptured line onto a hot engine and
maybe sparking broken electrical wiring. You are knocked out and now
the van bursts into flames. Is doing a repair right and spending a few
extra dollars or some extra time to troubleshoot a problem worth it? Of
course it is. Take it from someone who has been through a car fire
once, you never want to have to go through this, ever.
Ken Wilford
John 3:16
www.vanagain.com
Robert Keezer wrote:
> What is the safety issue with a constantly running pump? I know someone on this list who has a continuosly running pump on a aircooled Vanagon who says it's no big deal.
> he says it's no big deal, it's OK, you worry too much.
> I know it's not the original design but what could be the danger of a pump that runs constantly ?I'd like to know.
>
> Robert
> 1982 Westfalia
>
> --- On Mon, 5/11/09, Dave Arthur <dave.arthur@NSCC.CA> wrote:
>
>
> From: Dave Arthur <dave.arthur@NSCC.CA>
> Subject: Digifant Fuel System Troubleshooting Experience
> To: vanagon@GERRY.VANAGON.COM
> Date: Monday, May 11, 2009, 5:54 PM
>
>
> I hope I never get to be one of those PO (Previous Owners). I hate it when
> technicians(?) take short cuts and 'make it work'.
>
> I've been tracking down an uneven idle and decide it was time to do a test
> of the injectors. I work at a community college and borrowed an OTC kit, it
> consists of a pressure gauge and an electronic device to manually fire the
> injectors.
>
> The procedure is to fit the pressure gauge into the fuel system, turn on the
> ignition to pressurize the system (pump should shut off after 5 seconds),
> note the fuel pressure and then fire the injector (50 pulses at 1 ms per
> pulse was suggested), note the resulting fuel pressure and calculate the
> drop. All the injectors should have approximately the same drop which
> correlates to fuel passed through the injector. Now of course it doesn't
> evaluate pattern etc. but its a fast test.
>
> So I set up and turned on the ignition, the fuel pump runs continuously and
> doesn't turn off after 5 seconds. Being a new Vanagon owner I thought that
> this was normal... But I'm now suspicious.
>
> I checked the wiring diagram and see that the pump is actually run through a
> relay, that is controlled by the ECU. I removed the relay, turned on the
> ignition and the pump still ran. Turns out the PO/Tech had run a wire from
> terminal 15 on the coil directly to the pump. So ignition on, pump on.
>
> This of course is a huge safety issue ...
>
> I replaced the relay and connected the pump up properly and all was well,
> until I checked the fuel pressure. As soon as the pump stopped the fuel
> pressure bled down rapidly to zero (~2-3 sec). The manual expects at least
> 29 psi after ten minutes!
>
> I pinched off the fuel return line and individual injectors to test for leak
> down issues and concluded that the pump itself was not holding the pressure
> when it stopped.
>
> So the engine runs, but starts hard, with the pump running all the time as
> before, the engine started immediately.
>
> I guess I need to know my options. Could I put a check valve in the pressure
> side of the fuel line or should I bite the bullet and get a new pump?
>
> Dave
>
> '86 Westy
>
>
>
>
>
>
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