Date: Tue, 12 Apr 2011 12:07:54 -0700
Reply-To: Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Subject: Re: Fuel Pump No Juice
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first .,...
if you just need it to run ..
route a 'hot wire' temporarily to the postive teminal of the fuel pump.
Then it wil run if everything except fuel pump control is working.
I like to even connect something like that to a tail light ..
so the your light switch controls that temporary circuit.
I suspect you do not understand how the cirucit works.
here's how it works..
1. There is power to the fuel pump only when the fuel pump relay is
energized ( it's one of the two in that black box above the coil ..the other
is the 'main relay' ..that powers up the ECU ) .
2. The fuel pump Relay is energized by the ECU suppliing ground to the fuel
pump relay. ( if you found that wire at the fuel pump relay
.........disconnected itr so it's not connected to the the ecu, and grounded
it ....you would energize the fp relay 'manaully.'...like as a test or
emergency way to run the engine ) .
2.5 ....the ecu supplies ground two different times....one is when you just
turn the key 'on' ( NOT to 'start'...just on ) ...the ecu supplies grnd to
the fp relay for about 8 senconds...then disconnects.
It's always a good idea to start the van that way ..turn on key ..listen
for fp to run and shut off ..
and also check that the warning lights are working at the same time < a
check so often never done.,>
the other time the ecu supplies grnd to energize the fp relay is when the
ecu sees the distributor turning ..that also triggers the fp relay...by the
ecu supplying ground to it.
That's the only way the fuel pump ever gets power..
the ecu supplies ground to the fp relay to energize it.
so work on that system or cirucit.
you could have a bad fp relay ..but that's rare.
one should have a spare on of those relays around anyway , for testing and
self-rescue.
scott
www.turbovans.com
----- Original Message -----
From: "Kurt Grotz" <kgrotz@CRAFTECH.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Tuesday, April 12, 2011 10:42 AM
Subject: Fuel Pump No Juice
> Can't seem to figure out why I am not getting power to fuel pump.
>
> I hooked 12v up to fuel pump and it pumps!
>
> Replaced Fuel Filter
>
> Checked current at positive lead on fuel pump with ignition on...nothing
>
> It does run for a bit when I use ether starting spray, so it is getting
> ignition. Would that say ignition switch is ok?
>
> I replaced the fuel pump relay
>
> I followed the hard
> wiring from pump to engine compartment. Some of the connections were bad
> so I cleaned up or replaced. Still nothing to the pump when I turn the
> key to on.
>
> I hate to tow it to shop...and they hate to push it in from lot. :)
>
> Any last thoughts?