Date: Mon, 11 Jan 1999 14:13:47 -0600
Reply-To: Darrell Boehler <midwesty@MIDWEST.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Darrell Boehler <midwesty@MIDWEST.NET>
Subject: Re: Intermittent no start - fuel pump/relay?
Content-Type: text/plain; charset="iso-8859-1"
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Hi Art,
The fuel pump should always run a short time maybe 1 - 2 seconds as you
go from key off to key on. It should also run anytime there are hall pulses
from the distributor. If you are getting hall pulses you should also have
fi (fuel injector) pulses. This way using a stethoscope or by feel at an
injector you can tell if you have fuel pump or a hall problem. The ecu
controls both the fuel pump and the fi signals.
Darrell
-----Original Message-----
From: Beutler, Art (AZ75) <Art.Beutler@CAS.HONEYWELL.COM>
To: vanagon@GERRY.VANAGON.COM <vanagon@GERRY.VANAGON.COM>
Date: Monday, January 11, 1999 10:25 AM
Subject: Intermittent no start - fuel pump/relay?
>My 1986 vanagon has developed an interesting problem over the weekend - it
>either is very hard to start requiring alot of cranking or quits once
>started. Initially the problem was a refusal to start despite good
cranking
>- at the time I am pretty sure that I heard the fuel pump come on when I
>initially turned the key to the run position. Subsequently, it has started
>and run after a normal amount of cranking, started and run after a lot of
>cranking, refused to start after cranking forever, and died once started.
>
>While trying to troubleshoot the problem yesterday, I turned the key to run
>and noticed the fuel pump ran for a bit. Turning it off and back to run
>resulted in the characterisitc short whine. It then started with no
>problem. After running a while, I shut it off and tryed to restart. Now
>turning the key resulted in no whine and no start. After sitting overnight
>I get the same result.
>
>Should the fuel pump ALWAYS run when the key is turned to run? Does the
ECU
>have logic to sometimes run the pump and sometimes not when the vehicle is
>first fired up? If so, what sensors is this dependent on? Also, is a
>properly working fuel pump/relay unusually voltage sensitive? I would hope
>that if there is enough battery voltage to crank the starter there should
be
>enough to run the fuel pump/relay/ECU signal chain.
>
>One other thing I noticed (which brings up the voltage question) is that
the
>headlights were alternately dimming and brightening (as might happen with a
>flakey regulator) just before the onset of this problem. This has stopped
>happening but between this and all the cranking I am thinking the battery
is
>a bit low.
>
>I will put the battery on the charger tonight and start trying to do some
>real troubleshooting tomorrow, but any insights to the operation of this
>stuff would be appreciated!
>
> Art Beutler
>
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