[Vwdiesel] Leaking IP ; Fuel in the Sump

[brian gochnauer]

I also have a 1.6 NA 90' Jetta with that diaghram on top and a fuel leak,
but after reading recent posts, seems that it's probably the cold start seal
on the back of the pump.
Two cents;
I believe (relating my Caterpillar IP experience) that the diaphram is to
keep reduce the black smoke belch from the tail pipe relating to quick
throttle changes by sensing vacuum changes in the intake using the small
orfices and springs.
Caterpillar had a functional (spring/orfice) on their IP, to reduce belching
of smoke because of EPA standards and also because it's a waste of fuel.

On Mon, Jun 16, 2008 at 8:15 AM, Val Christian <val at mongo.mongobird.com>
wrote:

> Ref the posts below...
>
>
> I also have a ME, which is a non-turbo 1.6 on a 91 Jetta.  I recently
> reported fuel in the oil sump, and a timing problem.  The timing has been
> resolved.  The fuel in the sump has also been resolved.  Loren deserves
> credit on this one.  Here's what was happening:
>
> A failure in the IP, caused fuel to be fed into the vac pump.  It was a
> pretty good flow.  Loren suggested that the fuel contamination in the
> oil sump exceeded the rate the injectors were capable of.  So I went
> looking elsewhere.  Hayden shared his understanding of the fueling
> management of the 1.6 NA engine.
>
> Like the post below, I have an IP which ends in ...710 N.  It has
> a diaphram on the top, which is similar to what the turbos have
> (it may even be the same), except that it operates the opposite.
> The top of it is vented to the atmosphere, with a rubber boot
> having a opening in it.  The bottom of the diaphram is connected
> to a banjo fitting which has a 3mm vacuum/fuel return hose on it.
> That line runs to a T fitting.  The driver side of that T goes to
> an inline orifice, used to limit flow.  The passenger side of the
> T goes to a diaphram device near the fuel filter.  I can't tell
> you exactly what is happening with this circuit, perhaps Hayden
> can, but it appears that it is sensing the absolute pressure one is
> driving at, and using that to adjust fuel metering.  Hayden suggested
> it was probably an emissions thing.
>
> In my particular case, the failure was causing fuel to flow from the pump,
> through the vacuum orifice, into the vacuum pump, and discharged into
> the engine sump.  As a possible workaround, I disconnected the line from
> the
> IP to the compensation lines with the T fitting, and I found that
> fuel continued to leak.  First it seemed that fuel was oozing from
> the hose where i plugged it.  So I plumbed it into the return line
> going back to the tank.  Things were still leaking, then I discovered
> fuel oozing out of the rubber boot on the top of the diaphram.
>
> So at this point, it seems that I need to do some kind of IP repair,
> although it is not exactly clear to me what will need repair.
> So fi anyone knows, please speak up.  (Otherwise I will continue to
> pester Loren and Hayden.)
>
> So this ties in with the posts below, in that I can add a little
> understanding on the fuel de-enrichment mechanism for high altitude
> driving.
>
> Val
>
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> > --- In dieselvolkswagenclub at yahoogroups.com, "Wes Engle"
> > <hankbrass at ...> wrote:
> > >
> > > I am in the process of swaping a 79 CK (1.5) out of my 81 pickup in
> > favor of an 89 ME (1.6). I have a couple of questions. On my old
> > motor there is a crankcase breather plate that has a hose going to
> > the vacuum pump. The newer motor does not have this. Can I just run a
> > hose to my brake booster on the newer one? The other question
> > involves the injector pumps. The one on the ME has a diaphram like
> > pot on the top of the pump. I think this is a boost inrichment gizzy
> > for a turbo? On the back of the pump it has 2 banjo fittings. a lower
> > one with two hose barbs, large and small which I think are the
> > injector overflow and tank return line connections. The upper barb is
> > VERY small. Can I just leave this unconnected as the motor is not
> > turboed.
> > > Wesley A. Engle
> > > NRA Benefactor Member
> > > (and proud of it!)
> >
> > The diaphram on top of the injection pump is for turbo enrichment, it
> > shoul have a barb fitting on it for the boost signal. The other very
> > small barb fitting if for the return lines from the injectors. There
> > should be two larger fitting one for fuel supply and one for fuel
> > return from the tank.
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