Date: Sun, 10 Jul 2011 14:32:13 -0400
Reply-To: David Beierl <dbeierl@ATTGLOBAL.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: David Beierl <dbeierl@ATTGLOBAL.NET>
Subject: Re: power to the fuel pump
In-Reply-To: <1310318465.75365.YahooMailClassic@web180509.mail.gq1.yahoo .com>
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At 01:21 PM 7/10/2011, Gus Cairo wrote:
>the vehicle: 1982 air cooled California specs vanagon
>the problem: the van starts during the cranking cycle then dies
>when it loses fuel pressure
>steps I have taken: check fuel pressure at 28 during cranking cycle,
>checked AFM with ohms tester checks out OK, removed cover from
>double relay and watched the contacts both close when key is turned
>on (don't know if one or both are supposed to close at this time),
>Ran continuity test between pump switch in the AFM to the plug that
>goes to the double relay, all contacts showed continuity. with the
>AFM switch locked closed looked for voltage at the plug and found
>none although I think that the voltage probably runs the other way
>and the AFM just closes the circuit and send power to the fuel pump.
>Next I disconnected the wires at the fuel pump and attached a 12
>volt source from another car battery, started the van and it ran
>indefinitely as long as the outside power was supplied. I just can
>not figure why the pump is not getting power during the run cycle.
>Can anybody help. Thanks Gus
97.13 is easier to read than 97.19 - but there's a typo on both of
them. 97.13 track 22, it appears that 88c is connected to the relay
coil directly above it. This is not correct. 88c and 88d are
connected together and supply the +12v for the aux air regulator and
fuel pump. The relay coil is connected only to the 85 terminal at track 21.
During starting the fuel pump relay (right-hand one of the pair on
the drawing) is directly energized from the 50 terminal on the
ignition switch, by way of the blue/brown wire to terminal 86a on track 22.
Once the key is released it depends on the ECU relay (left-hand one)
which is energized from ignition switch terminal 15 by way of the
ignition coil and the black wire to terminal 86c on track 21. Its
contacts on track 19 supply +12 to the switch in the AFM, which
passes it on to terminal 86b on track 21+1, energizing the fuel pump
relay through an internal connection.
So...with ignition on, here's what you should see on the relay terminals:
88y and 88z, fat red wires - +12 directly from battery/starter connection.
85, white wire - zero or close to it.
88a, white wires - +12 through ECU relay to supply ECU and AFM switch.
86b, white wire - zero with AFM vane closed, +12v with vane open to
energize fuel pump relay.
88c, white wire to Aux Air Regulator - fuel pump relay output, zero
with AFM closed, +12v with vane open.
88d, red/black wire to fuel pump - ditto.
'Zat help?
Yours,
David
