Date: Wed, 28 Jan 2004 16:01:40 -0800
Reply-To: mark drillock <drillock@EARTHLINK.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: mark drillock <drillock@EARTHLINK.NET>
Subject: Re: 91(bus) dead on the freeway tech expertise needed !
Content-Type: text/plain; charset=us-ascii
You can make a small jumper to bypass each relay. Use 2" of 12 or 14
gauge wire. Put a male spade lug on each end. The .250" size, most
common, 5 for $1. Plug that jumper into the relay sockets across holes
30 and 87. That will simulate a working relay that is turned on. Make
sure to measure the back side of pin 87 on each socket as the key is
turned on or after the jumper is in. One relay turns on the ECU whenever
the key is on and the other turns on the fuel pump whenever the ECU
tells the relay to do so. The above jumper will not make the fuel pump
go unless the ECU is telling it to. The ECU runs the fuel pump for a
couple seconds each time the key is turned on. Does it?
The relays are a very common automotive type. About $5 and even
RadioShuck may have them as well as PoopBoys and Krapagen. Don't replace
them unless using the jumper makes the van start. Even then there could
be other causes.
It sounds like you need a Digitool. These instantly show some of the
more common faults that prevent starting. If you have no spark but do
have +12 at the coil, you could have a bad ECU, bad Hall unit in the
distributor, or wiring to these, grounds for these, coil, and that is
about it.
Is the fragile connector to the distributor in solid condition? These
often crack loose and then the tiny wires rub against the distributor
body until the insulation fails. Then the hall unit does not send pulses
to the ECU so the ECU does not try to fire the coil.
Mark
John Carpenter wrote:
>
> Hi All,
> Well, I got out the multimeter...
> Juice on the large red wire terminal on the fire wall.
> 12v at the coil. But no spark at the plugs.
> No fuel pump either.
> 12v at the key switch. It seems to be working.
> I both checked the voltage at #4 relay slot, and replaced the switch, as well.
> I seem to have power to the two relays in the black box, drivers side, engine
> compartment.
> Next, those relays? I put 12v to the switch sides, on the relays, #85 & 86, I
> think.
> they do (sound) like they are working, but how do I know for sure?
> Can they be bought at flaps?
> Or just the VW places?
> Thanks to everyone for their help!
> I've studied the manual, & I just get more confused?
> But your systematic approach is helping immensely!
> thanks again,
> John C
> SLC, UT
> 91 CRANKER, BUT NO STARTER....YET! :)
>
> In a message dated 1/28/04 10:42:00 AM Mountain Standard Time,
> twombleyw@JPS.NET writes:
> On 1/28/04 8:55 AM, "mark drillock" <drillock@EARTHLINK.NET> wrote:
>
> > You can easily test to see if the ignition switch is the cause. The
> > switch uses a separate contact for the starter and another to turn on
> > the ECU and ignition. The starter contact is obviously working. The
> > other contact may be bad. You can test it at the relay panel. There is
> > an empty relay socket in position #2. The 8 holes where a relay could
> > plug in make convenient test points. Hole number 4 is connected to the
> > ignition switch contact that turns on the ignition coil and ECU. Connect
> > a voltmeter probe between hole 4 of relay socket#2 and ground. You
> > should have +12 volts or so whenever the key is turned to ant on
> > position. There should be 0 volts with the key off. If you have +12
> > volts there during cranking and the engine does not start then the
> > switch is NOT the problem.
> >
> > Mark
> >
> > John Carpenter wrote:
> >>
> >> Thanks Joel,
> >> I went down to the bus this morning, and there is No fuel pump, initial
> >> surge. Also no spark. I will change the key switch first, then test those
> >> relays.
> >> What is the best way to check them?
> >> Thanks for your help!
> >> John C.
> >> SLC, UT
> >> 91 Westy...
> >>
> Mark
| 
