[T3] my long term issue have to unplug TS1 for a smooth idle.
willjahn975 at gmail.com
Mon Sep 30 16:01:53 PDT 2019
Yes I took mine all apart because it was sticking partially open. I also
adjusted the set point so it would close sooner , moved the spring as far
as it would move in the springs slot. I checked it just the other day just
putting power to it and it closed and once it cooled off it opens. I will
tell you it closes a lot quicker just powered up and gets quite hot yet
when the vacuum from the IAD line is pulling air through the valve it seems
to cool the entire valve down making it take much longer to close fully yet
it does. I'm sure @ 1200 RPM the timing is advancing. It was 75*F when I
drove it today and it acts the same way @ 90*F .
I watched the valve work after I took it apart and cleaned and adjusted
it. I could see the valve slot was fully exposed then it would rotate where
I could not see the slot at all. The only thing that makes sense with the
low RPM is if it does stick closed yet I have not been able to find it
doing this. I will have to check if it's open cold I can't see any reason
it would stick closed I tested it quite a few times saw it was open fully
then powered it up and watched it close fully. The only way to really know
is pull the hose from the IAD to the AAR and look before I start it. You
can only see the slot from the IAD side.
I have no idea what would cause this low startup RPM if the valve is open
cold . The entire point of the AAR is to be a vacuum leak to only richen
the mix by causing the MPS to keep the injectors to stay open a bit longer
along with TS2 and partly TS1. When my AAR was having issues sticking open
where I could feel the suction I would sometimes have success tapping the
top with a screw driver handle and it would close so I knew it was open not
how much and it still had this low cold start RPM . It's a complete mystery
to me. I know TS2 and TS1 read what they should cold and both drop. At this
point all I can do is check the AAR cold then go from there.
On Mon, Sep 30, 2019 at 2:52 PM Jim Adney <jadney at vwtype3.org> wrote:
> On 30 Sep 2019 at 13:16, William Jahn wrote:
> > The idle didn't hang like it did before. Still when I first started it
> > RPM was a bit higher than 850 it increased by 50 RPM and it then climbed
> > 1200 seems there is a lag before the AAR brings the idle up yet it does
> > to 1200 faster.
> The AAR should be partly open when you first start, and then close off
> completely once the engine is warmed up. But what if yours is sticky? If
> only moves under engine vibration, it might remain fully closed as the
> engine cools down. That would give you a low idle when you first start up,
> but would then increase the idle as the vibration lets it open. As the
> and the AAR warm up, the AAR would close down again.
> You can test this by putting your thumb over the hose leading to the AAR.
> it does nothing when the idle is ~900 but slows things down when the idle
> has risen to ~1200, you know that it's at least partly due to the AAR
> > I don't have anything to compare the way mine starts with. Jim when you
> > start your 73 what do you notice ?
> My idle starts out a bit high, then slows down as the AAR warms up and
> closes. In other words, the AAR seems to be working correctly. I don't
> my idle every gets even close to 1200. The AAR is NOT actually supposed
> to increase the idle speed at all. It's supposed to increase the engine
> when it's cold. Ideally, this would be just enough to overcome the
> friction of the cold oil.
> Note that the idle speed should be set with the engine warm and the AAR
> fully closed.
> If the balance between the AAR opening and the viscosity of the oil is not
> perfect, and it never is, the idle speed of a cold engine in cold weather
> be diffeent from what it's set at when hot.
> When your idle speed gets up toward 1200, that will start to bring the
> advance into play, which will increase the RPMs even more. It's possible
> you have the AAR closing at too high a temp. The adjustment does not
> inclrease or decrease the total opening amount, it only changes the
> temperature range over which the opening occurs. There will always be
> some temp when the AAR is fully open and another when it is fully closed.
> I think you took your AT AAR apart and cleaned and adjusted it. I've never
> taken one of those apart, but I've done lots of the MT ones. This has me
> wondering if you have yours closing at too high a temp.
> Jim Adney, jadney at vwtype3.org
> Madison, Wisconsin, USA
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