Date: Mon, 11 May 2009 18:52:18 -0700
Reply-To: Don Hanson <dhanson928@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Don Hanson <dhanson928@GMAIL.COM>
Subject: Re: Digifant Fuel System Troubleshooting Experience
In-Reply-To: <C62E4F1D.7CB4%dave.arthur@nscc.ca>
Content-Type: text/plain; charset=ISO-8859-1
I'd say, "a new pump"...But I sometimes have a dumb habit of 'throwing parts
at a problem". But you will then have a somewhat servicable spare pump to
carry along if and when you travel...Another thing to check is the condition
of your fuel lines and hoses. Make sure they aren't "fixed" somehow
dangerous by that PO and see if they've ever been replaced..Many a vanagon
has gone up in flames from old leaky fuel lines...You might have some leaks
there causing your fuel pressure to bleed off.
Don Hanson
On Mon, May 11, 2009 at 5:54 PM, Dave Arthur <dave.arthur@nscc.ca> wrote:
> 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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