Date: Fri, 27 Jul 2007 01:47:38 -0700
Reply-To: Scott Daniel - Shazam <scottdaniel@TURBOVANS.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Scott Daniel - Shazam <scottdaniel@TURBOVANS.COM>
Subject: Re: Is ECU involved in getting power to fuel pump when turning
seque to diesel radiator coolant flow direction
In-Reply-To: <000001c7d005$41d301f0$0201a8c0@DADSTOSHIBA>
Content-Type: text/plain; charset="us-ascii"
Hmmmm.....
Ok, you're saying putting the hot coolant in at the bottom of the radiator
aids bleeding, and bleeding would be a problem if hot coolant entered at
the top of the radiator.
Okaaay.....I'll think about that for a while.
Thanks , scott
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Dennis Haynes
Sent: Thursday, July 26, 2007 7:44 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Is ECU involved in getting power to fuel pump when turning
seque to diesel radiator coolant flow direction
The Vanagon Radiator has to flow reverse in order to properly bleed.
Looking at the radiator, there is a fitting that faces the rear of the
van. That is the feed. It should be connected to the main tube on the
right. The straight down fitting on the radiator, directly under the
bleeder, is the return to the thermostat housing. Reverse these
connections and getting the air out is a sporadic adventure.
Dennis
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
David Kao
Sent: Thursday, July 26, 2007 10:08 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Is ECU involved in getting power to fuel pump when turning
seque to diesel radiator coolant flow direction
California weather is like magic. Both my 83 and 84 never had a single
problem so far in either radiator. I can see a little surface rust but
never any leak or any performance issue whatsoever. That has made me
completely inexperienced with anything associated with Vanagon radiators.
On the other hand it's good to be free from radiator troubles.
Just a gut feeling that hot coolant should enter from the top and the
cooled
come out from the bottom. I think I had a correct guess.
Thanks for confirming it.
David
--- Scott Daniel - Shazam <scottdaniel@turbovans.com> wrote:
> Hi David,
> 'normally' hot coolant enters radiators at the top, cool comes out the
> bottom.
> All vanagon radiators are cross flow - two cross flow radiators stacked
on
> top of each other I believe...
> Still though, you'd expect hot to enter the top, cooler to come out the
> bottom.
> s.
>
> -----Original Message-----
> From: David Kao [mailto:dtkao0205@yahoo.com]
> Sent: Thursday, July 26, 2007 4:30 PM
> To: Scott Daniel - Shazam
> Subject: RE: Is ECU involved in getting power to fuel pump when turning
> seque to diesel raditaor coolant flow direction
>
> Scott, this is a tough question for me. I know nothing about Diesel
> Vanagons.
> Never seen one in California. I will look at my Bentley manual to see if
I
> can
> find any info about it. I will email you if I find something.
>
> It seems hot coolant should enter the radiator from the bottom. But if
it
> enters
> from the top it seems the returning coolant back to the engine has less
> chance
> to get air in it. Cooling requirement for diesel may be less critical
than
> for gas engine? I don't know for sure.
>
> David
>
> --- Scott Daniel - Shazam <scottdaniel@turbovans.com> wrote:
>
> > Thanks, yes me too, hope it helps make vanagon owning and care more
> > rewarding and successful for people !
> >
> > Ps, now tell me if diesel vanagon coolant flow through the radiator is
> > backwards or not.
> >
> > I've studied the Bentley, looked at two diesel vanagons, and Marie has
> > too....and it sure looks like hot coolant exits the engine at the
cylinder
> > head, but flows not to the top of the radiator, but to the bottom,
which
> is
> > backwards from what you'd expect to see.
> >
> > I 'm still gong to go look at these two D. vanagons here to confirm
that
> > some more.
> > There's one piece of confusing info on page 19.5 . where it says 'to
> > cylinder head' that implies flow in that direction, it should really
say
> > 'from cylinder head'
> > Just like it says 'from radiator' at the thermostat connection on page
> 19.4.
> > So don't let that throw ya.
> > scott
> > www.turbovans.com
> >
> > -----Original Message-----
> > From: David Kao [mailto:dtkao0205@yahoo.com]
> > Sent: Thursday, July 26, 2007 2:44 PM
> > To: Scott Daniel - Shazam; 'David Kao'
> > Subject: RE: Is ECU involved in getting power to fuel pump when
turning
> > ignition switch on?
> >
> > Thanks for the good brain storming exercise of Vanagon electrical
circuit.
> > Hope there are usefull info for listees.
> >
> > David
> >
> >
> > --- Scott Daniel - Shazam <scottdaniel@turbovans.com> wrote:
> >
> > > Exactly.
> > >
> > > -----Original Message-----
> > > From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On
Behalf
> Of
> > > David Kao
> > > Sent: Thursday, July 26, 2007 12:52 PM
> > > To: vanagon@GERRY.VANAGON.COM
> > > Subject: Re: Is ECU involved in getting power to fuel pump when
turning
> > > ignition switch on?
> > >
> > > Electricity flowing from positive voltage point to negative point is
> just
> > > a concept for convenience. It is closer to the reality that it is
> > electrons
> > > that moves in the opposite direction. For AC current the electrons
are
> > > moving back and forth. They never really flow to anywhere.
> > >
> > > The best way to describe how the ignition coil works is to look at
it in
> > > a current point of view. It would be necessary to look at a voltage
> point
> > > of view if the device is a capacitor.
> > >
> > > Basically the primary winding of the coil needs to have an initial
DC
> > > current
> > > flowing to produce maximum magnetic field at the iron core. To
induce a
> > high
> > > voltage across the secondary winding you cut off the current as fast
as
> > you
> > > can. The high voltage produced across the secondary winding is an
> induced
> > > EMF
> > > by the rapid collapse of the magnetic field in the iron core.
> > >
> > > Dennis explained this correctly in an easier to understand fashion.
ECU
> > pin
> > > #25
> > > should be grounded initially and is switched to open (to cut off
> current)
> > > upon
> > > seeing the Hall signal than quickly back to grounded state waiting
for
> the
> > > next
> > > Hall signal. It is really an electronic point that doesn't arc and
> doesn't
> > > wear.
> > >
> > > David
> > >
> > >
> > >
> > > --- Scott Daniel - Shazam <scottdaniel@TURBOVANS.COM> wrote:
> > >
> > > > Hi.
> > > > I've heard that electricity 'actually' flows from negative to
positive
> > all
> > > > right, but in practice it is considered to flow, DC is, from
positive
> to
> > > > negative. That's why ground is at the bottom of the Bentley
diagrams,
> > and
> > > > the fuse box ( positive ) voltage is across the top.
> > > >
> > > > Looking at it the conventional way like this, pin 25 is not a
source
> of
> > > > voltage.
> > > >
> > > > Right, on almost all cars, the ignition circuit is unfused.
> > > > There is no fuse anywhere between positive voltage and pin 15 on
the
> > coil.
> > > >
> > > > Then we are in agreement and understand the circuit the same way.
> > > >
> > > > 'most' switching take place on the positive side of the circuit,
but
> it
> > > > doesn't have to of course, could just as easily take place in the
> > > negative
> > > > side.
> > > > The horn circuit is an example of switching in the ground side.
> > > > Relays also - the ECU supplies ground to complete the pathway for
the
> > > small
> > > > windings in the fuel pump relay, another example of switching in
the
> > > ground
> > > > side of a circuit.
> > > >
> > > > scott
> > > > -----Original Message-----
> > > > From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On
> Behalf
> > Of
> > > > Dennis Haynes
> > > > Sent: Thursday, July 26, 2007 4:52 AM
> > > > To: vanagon@GERRY.VANAGON.COM
> > > > Subject: Re: Is ECU involved in getting power to fuel pump when
> turning
> > > > ignition switch on?
> > > >
> > > > If you go with the fact that electrons are actually flowing from
the
> > > > negative terminal of the battery to the positive, then you are
correct
> > > that
> > > > pin #25 is a source. Since most folks see the positive as the
source
> and
> > > the
> > > > negative as the "ground", ( which it really isn't) or common, we
see
> the
> > > > positive and most switced connections as the source. This is
called
> > > > conventional current flow.
> > > >
> > > > Except for the wire from the ignition switch going through the
fuse
> box,
> > > #15
> > > > on the coil is feed directly off the ignition switch. There is not
> even
> > a
> > > > fuse in the way. Pin #25 completes the path to the chassis to
control
> > the
> > > > coil as you described. This is known as a "sinking" control
circuit.
> > > >
> > > > Dennis
> > > >
> > > >
> > > > >From: David Kao <dtkao0205@YAHOO.COM>
> > > > >Reply-To: David Kao <dtkao0205@YAHOO.COM>
> > > > >To: vanagon@GERRY.VANAGON.COM
> > > > >Subject: Re: Is ECU involved in getting power to fuel pump when
> turning
> > > > > ignition switch on?
> > > > >Date: Wed, 25 Jul 2007 21:11:37 -0700
> > > > >
> > > > >On the Bentley manual the #1 terminal is connected to the ECU's
pin
> > #25.
>
=== message truncated ===
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