Date:         Wed, 2 Mar 2011 10:08:34 -0500
Reply-To:     Pascal Giasson <pascal.giasson@GNB.CA>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Pascal Giasson <pascal.giasson@GNB.CA>
Subject:      Re: Cruise control progress

While searching for a replacement cruise control kit I discoverd this in
the archives, that describes what is happening to my Equus vacuum cruise
control.  I have a 8"x4" diameter vacuum canister that I built out of PVC
pipe and instaled a check valve.

What happens when going up long hill and it goes to full throttle, the
servo stick open at full throttle. Not fun at all.  I've tinkered with it
for the last 4 years thinking that it was a mechanical issue, but the last
time I pulled over and I had to pull very hard on the servo cable to get it
to let go, which confirmed to me that it was the servo.  Now after reading
this thread in the archives, I'm wondering if my home made vacuum canister
if too big and builds up too much vacuum and sticks the servo in full
throttle and keeps it there.  Any thought?  Anyone else have a similar
experience?

BTW, it's not the kind of things that is too much fun experimenting with...

Thanks

Pascal
'84Westy



On Mon, 06 Jan 1997 15:03:00 -0500 (EST), Porter_Fred%
PAX9@mr.nawcad.navy.mil wrote:

>
>Today I talked to the Equus cruise control Technical Service dept.
>(800-544-4124) and they were super helpful!  I talked with Gene--he has
>installed the system on his 84 westy and had some detailed modifications to
>make the system work.  Equus does not recommend the system for the vanagon
>because of the low vacuum levels supplied by the engine.
>
>The vacuum on the vanagons is not enough to run the cruise control so at a
>minimum a vacuum canister with check valve needs to be installed to build
up
>a resevoir of vacuum to power the servo.  Gene recommended to call Napa and
>ask for part no. 250-6019 from the Perfect Circle catalog.  It will
probably
>look like a can with two ports on it.  It also has a check valve so that
>vacuum can be 'acumulated' inthe canister.  For junkyard scavengers, look
>for late model GM's or call automotive heating and A/C types.  It is
>IMPORTANT that the canister have two vacuum fittings and that the flow only
>goes one way.  If you suck on one side you should be able to feel it on the
>other port in only one orientation because there is a check valve in the
can
>to permit only one way flow.  Even with the canister, operation at altitude
>is still questionable.
>
>Gene suggested hooking up the vacuum feed line to where the line goes
>forward to the power brake booster.  Right now, mine is taping off the idle
>stabilizer valve connection to the inlet air distributor.  That may be a
low
>and inconsistent source of vacuum.
>
>Gene also said that a vacuum pump is to powerful.  They typically supply
>18-20" of steady vacuum and the unit only needs about 10-16".  Using a
>vacuum pump could result in a stuck valve and an inadvertent full throttle
>condition.  Yeuch.
>
>Considering the above two scenarios, I think that after I move to Utah,
I'll
>be modifying my cruise control to have its own independant vacuum pump, but
>will run it through a vacuum canister with a pressure relief valve.  This
>way I'll be able to have a steady supply of strong but meterable vacuum.
>  The vacuum pump will be hooked up to the canister which will be hooked up
>to the cruise control servo.  If the vacuum becomes to strong for the
servo,
>the pressure relief valve will allow some air into the system reducing the
>level of vacuum.  Having the canister in line will reduce the systems
>sensitivity to valve operation and make the vacuum level more consistent.
> By hooking up a vacuum gauge on the exit of the canister, I'll be able to
>set the release point for the relief valve.  This should allow the servo to
>operate at altitude.  For safety sake, the power to the vacuum pump could
>also be controlled by a pressure sensor on the canister.  At a minimum, the
>power supply to the pump could be in series with the power supply to the
>servo--kill both with one wire yank at the fuse block.
>
>If all this fails, Gene recommended an all electric system made by Rostra
>(previously Dana) in North Carolina, 910-276-4853
>
>BTW, the stock VW cruise control system for the vanagons has a vacuum
system
>independant of the engine.  It has its own vacuum pump.
>
>I've mentioned several companies here, but have no affiliation with or
>interests in them.
>
>later,
>Fred porter
>