Date: Thu, 25 Oct 2007 07:42:01 -0700
Reply-To: Michael Elliott <camping.elliott@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Michael Elliott <camping.elliott@GMAIL.COM>
Subject: Re: Manifold measuring - is this right?
In-Reply-To: <71d9cdf90710250016i72d37137p51bda792b791ca2f@mail.gmail.com>
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Hi Jake, more good questions! Maybe I can provide useful answers from this
1984 1.9L
> 1 . Does the idle go down/smooth out when you put your thumb over the
> opening? You have just created a vacuum leak by pulling the hose off,
> right?
I have played with the fuel reg hose (well, not played, that sounds too
odd) by plugging/unplugging it, and when unplugged the rpms don't change
noticeably though the engine runs rougher. I don't know what the heck this
result suggests. Maybe a better test is to do the plug/unplug test with
the ISCU bypassed? Won't that thing try to keep the idle constant?
> 2. If you're only getting 10, you've got a leak.
Yorp. Seems to be the case all right. I'll be trying a friend's gauge
later this morning to confirm.
> 3. Like I said, it might be on the other side of the butterfly.
The intake side?
> 6. What happens when you disconnect the crankcase breather hose ? And
> when you put your thumb/whatever over/in it?
You're the second person who has asked about that. I am not seeing things
correctly -- that hose appears to connect to the intake side of the
butterfly . . . how could that affect vacuum? Isn't the AFM just a big
floppy door to the outside world?
> I was just poking around the illustrations, and there are two nipples on the
> left side of the plenum, one for the pressure regulator and one for .......what?
> The big one on the right side has ALL the vacuum gubbinses attached.
> I would check to see what happened when I took the main hose off there
> and covered the hole with my thumb
Bentley's (and my engine) have two hoses on the left side, as you observe.
One does the fuel reg, the other goes up through the firewall. Brake
booster, presumably? Yeah, maybe a leak going that-a-ways?
Thanks for the help!
--
Mike "Rocket J Squirrel" Elliott
71 Type 2: the Wonderbus
84 Westfalia: Mellow Yellow ("The Electrical Banana")
74 Utility Trailer. Ladybug Trailer, Inc., San Juan Capistrano
KG6RCR
On 10/25/2007 12:16 AM Jake de Villiers wrote:
> Hey Rocky, why don't you go ahead and put a couple of nice hi-res pix of
> the stars of your show up on your GooglePage for us to look at.
>
> The hose labelled "2" might be the advance line to the distributor. If
> it is, it might (a) have a restrictor in the line and (b) coming from as
> port that is closed/partly closed at idle.
>
> With regards to:
>
> 1 . Does the idle go down/smooth out when you put your thumb over the
> opening? You have just created a vacuum leak by pulling the hose off,
> right?
>
> 2. If you're only getting 10, you've got a leak.
>
> 3. Like I said, it might be on the other side of the butterfly.
>
> 6. What happens when you disconnect the crankcase breather hose ? And
> when you put your thumb/whatever over/in it?
>
> I'm working from an iffy scan of the Bentley, which is good because its
> dark & rainy out, but the photos suck.
>
> I'll try to make time to eyeball my own 1.9 tomorrow. Something may
> suggest itself.
>
> Which were your rich cylinders again? Or were they oily?
>
> Seeya, Jake
>
> On 10/24/07, *Michael Elliott* <camping.elliott@gmail.com
> <mailto:camping.elliott@gmail.com>> wrote:
>
> Thanks, Jake.
>
> I wonder if these vac findings make any sense at all:
>
> 1. I have been told that if the engine runs differently with/without the
> fuel pressure regulator vac line hooked up -- like idles too high
> with it
> disconnected -- it is a vacuum leak symptom. My engine runs a little
> rougher with the hose disconnected, but barely changes speed, if at all.
> This seems like I don't have a leak.
>
> 2. Vac at the fuel reg port reads 10'', and if I give it some throttle,
> the vac decreases. As you say, this is normal behavior, but the
> vacuum is
> pretty low at idle, suggesting that I have a leak.
>
> 3. Vac from the vacuum unit hose labeled "2" on the left hand photo on
> page 24.25 in Bentleys* (hose disconnected from vacuum unit) is
> about 11''
> when the engine is idling, but it will climb up to 18'' or more if I
> give
> the engine some gas. I don't even know whether this means anything
> at all,
> but it's different behavior than when I measure at the fuel reg port.
>
> 4. If I pinch the aux air regulator hose per Bentley's when the
> engine is
> cold (AAR is open at first as it should be, I've benched it) the engine
> does not slow as it is supposed to. This suggests a vac leak, else what
> does the AAR do for a living?
>
> 5. I've tried to find a leak by spreading hydrocarbons, like carb
> cleaner
> and propane hither and yon around any and all joints and hoses
> associated
> with the intake manifold and the engine doesn't change speed at all,
> ever.
> Suggesting I don't have a leak.
>
> 6. And an odd side finding: Fuel pressure reads around 35psi with
> that #2
> vac line connected, but drops to about 32 with it disconnected (and
> rpms
> increase) though Bentley's says the pressure should be about 29 with the
> hose connected and it should INCREASE to 36 or so with it disconnected.
> This behavior is opposite of what it is supposed to be.
>
> Folks who know how these things are supposed to work are so
> impressed with
> this latter finding that one said that the hoses must be hooked up
> improperly (they aren't), and another would like to see it for himself.
> I'm charging admission.
>
> * What is the name of that hose?
>
> --
> Mike "Rocket J Squirrel" Elliott
> 71 Type 2: the Wonderbus
> 84 Westfalia: Mellow Yellow ("The Electrical Banana")
> 74 Utility Trailer. Ladybug Trailer, Inc., San Juan Capistrano
> KG6RCR
>
>
>
> On 10/24/2007 6:50 PM Jake de Villiers wrote:
>
> > Well, you can read it for different situations, but idle is where you
> > need to be if you're looking for leaks.
> >
> > The throttle plate is closed, so the vacuum is pulling harder at
> any gaps.
> >
> > On 10/24/07, *Mike Rocket J Squirrel Elliott* <
> camping.elliott@gmail.com <mailto:camping.elliott@gmail.com>
> > <mailto:camping.elliott@gmail.com
> <mailto:camping.elliott@gmail.com>>> wrote:
> >
> > Should the engine be idling, or what, when measuring vacuum?
> Could be
> > doing this wrong.
> > --
> >
> > Mike "Rocket J Squirrel" Elliott
> > 71 Type 2: the Wonderbus
> > 84 Westfalia: Mellow Yellow ("The Electrical Banana")
> > 74 Utility Trailer. Ladybug Trailer, Inc., San Juan Capistrano
> > KG6RCR
> >
> > On 10/24/2007 4:34 PM Mark Drillock wrote:
> >
> > > I would use the vacuum line to the fuel pressure regulator.
> > >
> > > Mark
> > >
> > > Mike "Rocket J Squirrel" Elliott wrote:
> > >
> > >> Hi, I'm looking for leaks in the intake manifold. Bentley's
> > doesn't give
> > >> a procedure for checking intake manifold vacuum so I'm
> winging
> > it. I let
> > >> the engine warm up so that aux air regulator thing is
> closed,
> > and then I
> > >> pulled one of the hoses going to the vacuum unit on the
> dizzie and
> > >> connected it to my fine Harbor Freight vacuum gauge.
> > >>
> > >> This is a 1.9L engine and the hose I'm using is the hose
> labeled
> > "2" on
> > >> the left hand photo on page 24.25 in Bentleys.I don't
> know how
> > >> appropriate this hose is, but it has fewer bits connected
> to it
> > than the
> > >> other one. There's also a hose going to the fuel pressure
> regulator,
> > >> maybe it's a better choice?
> > >>
> > >> ANYWAYS, when the hose is disconnected from the vacuum
> unit, the
> > idle
> > >> hunts up and down. The vacuum gauge shows around 18psi --
> > depending on
> > >> engine rpms. I can open the throttle and the vacuum might
> drop
> > to 10psi,
> > >> then climb back up . . . I really have no idea how one
> goes about
> > >> measuring vacuum.
> > >>
> > >> --
> > >>
> > >> Mike "Rocket J Squirrel" Elliott
> > >> 71 Type 2: the Wonderbus
> > >> 84 Westfalia: Mellow Yellow ("The Electrical Banana")
> > >> 74 Utility Trailer. Ladybug Trailer, Inc., San Juan
> Capistrano
> > >> KG6RCR
> > >>
> > >
> >
> >
> >
> >
> > --
> > Jake
> > 1984 Vanagon GL
> > 1986 Westy Weekender "Dixie"
> > www.crescentbeachguitar.com <http://www.crescentbeachguitar.com>
> <http://www.crescentbeachguitar.com>
> > http://subyjake.googlepages.com/
>
>
>
>
> --
> Jake
> 1984 Vanagon GL
> 1986 Westy Weekender "Dixie"**
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