81 Scirocco smog check fixes update

"dave AKA vwdoc1" > wrote in message
...
> OK just say the idle is higher. When I hear worse I think of a rough &
> shaking engine that is about to stall/die.

So long as I'm willing to put up with high idle it runs fine.

> What did you do to the windshield washer again?

I misinterpreted the line that runs into the firewall and under the
windshield washer bottle. I don't know what it's for or where it goes, only
that disconnecting it has no effect. There's another line that runs from a
valve near the brake booster (which connects to the hose that runs to the
aux air valve and also connects to the vacuum advance). My Clymer manual has
nothing regarding those lines or the valve. Photos of them are he
http://hpaa.com/autos
I suspect the valve has something to do with altitude adjustments. I haven't
tried blocking the hose.

> Are you sure the vacuum unit is not leaking and is working?

Sucking on the hoses causes visible movement of the Hall sensor. The
mechanical advance moves freely.

> See if you can allow the throttle to close more.

First thing this morning I checked this and was able to back off the screw
maybe a few degrees. Engine started right up and idled at about 800rpm
(rough due to overlean CO). I upped the CO 1/8 turn to smooth the engine and
idle was still below 1K. I thought maybe I was good to go, but as the engine
warmed the idle went back above 1K.

> Some PCV hoses had a restrictor inside of them so it did not cause too
> massive a vacuum leak! Clamp that hose close while the engine is running.
> Did you change this hose?

Actually removed the hose and blocked the hole. No change. Engine has no
EGR.

Much thanks for the suggestions.

nutso fasst wrote:
> "dave AKA vwdoc1" > wrote in message
> ...
>> OK just say the idle is higher. When I hear worse I think of a rough &
>> shaking engine that is about to stall/die.
>
> So long as I'm willing to put up with high idle it runs fine.
>
>> What did you do to the windshield washer again?
>
> I misinterpreted the line that runs into the firewall and under the
> windshield washer bottle. I don't know what it's for or where it goes, only
> that disconnecting it has no effect. There's another line that runs from a
> valve near the brake booster (which connects to the hose that runs to the
> aux air valve and also connects to the vacuum advance). My Clymer manual has
> nothing regarding those lines or the valve. Photos of them are he
> http://hpaa.com/autos
> I suspect the valve has something to do with altitude adjustments. I haven't
> tried blocking the hose.
>
>> Are you sure the vacuum unit is not leaking and is working?
>
> Sucking on the hoses causes visible movement of the Hall sensor. The
> mechanical advance moves freely.
>
>> See if you can allow the throttle to close more.
>
> First thing this morning I checked this and was able to back off the screw
> maybe a few degrees. Engine started right up and idled at about 800rpm
> (rough due to overlean CO). I upped the CO 1/8 turn to smooth the engine and
> idle was still below 1K. I thought maybe I was good to go, but as the engine
> warmed the idle went back above 1K.

sounds to me like the AAV isn't closing... have you tried unplugging it
with the engine at warm idle? If that slows it down then maybe your
thermo-time switch is bad?

nate

>
>> Some PCV hoses had a restrictor inside of them so it did not cause too
>> massive a vacuum leak! Clamp that hose close while the engine is running.
>> Did you change this hose?
>
> Actually removed the hose and blocked the hole. No change. Engine has no
> EGR.
>
> Much thanks for the suggestions.
>
>


--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel

"Nate Nagel" > wrote in message
...
> sounds to me like the AAV isn't closing... have you tried unplugging it
> with the engine at warm idle? If that slows it down then maybe your
> thermo-time switch is bad?

I tried pinching the AAV hose shut with smooth channellock pliers and idle
did not change.

What role does the thermo time switch play? The test described in the Clymer
manual makes no sense (connect a test light between the terminals...?!).

Thanks,
nf

You have a vacuum leak or multiple leaks!
Plug everything to the intake manifold but the throttle body.
If it still idles high it would have to be the throttle body or intake
manifold!

"nutso fasst" > wrote in message
...
>
> "Nate Nagel" > wrote in message
> ...
>> sounds to me like the AAV isn't closing... have you tried unplugging it
>> with the engine at warm idle? If that slows it down then maybe your
>> thermo-time switch is bad?
>
> I tried pinching the AAV hose shut with smooth channellock pliers and idle
> did not change.
>
> What role does the thermo time switch play? The test described in the
> Clymer
> manual makes no sense (connect a test light between the terminals...?!).
>
> Thanks,
> nf
>
>

"dave AKA vwdoc1" > wrote in message
...
> You have a vacuum leak or multiple leaks!
> Plug everything to the intake manifold but the throttle body.
> If it still idles high it would have to be the throttle body or intake
> manifold!

OK, I began checking again. There IS some air leaking into the manifold
through the hose that connects to the valve cover. Completely sealing it
lowers the idle ~100 rpm (still doesn't stop the engine even with idle air
screw all the way in). I went to a parts store that still had the hose (049
103 223 D). The new hose was completely unrestrictive as regards incoming
air. No point buying it. How could it possibly stop the air from the
crankcase? This leakage must have been there since new.

Keep looking! :-)

Maybe a restrictor somewhere in that connection, like even on the intake
manifold pipe. If that hose has never been changed then all should be good.
Maybe I am remembering a water hose instead??????

Keep looking! :-)

"nutso fasst" > wrote in message
...
>
> "dave AKA vwdoc1" > wrote in message
> ...
>> You have a vacuum leak or multiple leaks!
>> Plug everything to the intake manifold but the throttle body.
>> If it still idles high it would have to be the throttle body or intake
>> manifold!
>
> OK, I began checking again. There IS some air leaking into the manifold
> through the hose that connects to the valve cover. Completely sealing it
> lowers the idle ~100 rpm (still doesn't stop the engine even with idle air
> screw all the way in). I went to a parts store that still had the hose
> (049
> 103 223 D). The new hose was completely unrestrictive as regards incoming
> air. No point buying it. How could it possibly stop the air from the
> crankcase? This leakage must have been there since new.
>
>

No, your memory is correct. I think there was a metal plug with a hole
in the middle. So instead of that hose being 13 mm ID it was 3 mm or
something like that. Just for fun he could get a big C clamp or an
alligator nose Vise Grip to close off that hose. That would almost
simulate the missing plug. If the idle drops way down you found one of
your problems. Once again it could be a lot of problems, not just one.

On Fri, 26 Sep 2008 21:14:05 -0500, "dave AKA vwdoc1"
> wrote:

>Keep looking! :-)
>
>Maybe a restrictor somewhere in that connection, like even on the intake
>manifold pipe. If that hose has never been changed then all should be good.
>Maybe I am remembering a water hose instead??????
>
>Keep looking! :-)
>
>"nutso fasst" > wrote in message
...
>>
>> "dave AKA vwdoc1" > wrote in message
>> ...
>>> You have a vacuum leak or multiple leaks!
>>> Plug everything to the intake manifold but the throttle body.
>>> If it still idles high it would have to be the throttle body or intake
>>> manifold!
>>
>> OK, I began checking again. There IS some air leaking into the manifold
>> through the hose that connects to the valve cover. Completely sealing it
>> lowers the idle ~100 rpm (still doesn't stop the engine even with idle air
>> screw all the way in). I went to a parts store that still had the hose
>> (049
>> 103 223 D). The new hose was completely unrestrictive as regards incoming
>> air. No point buying it. How could it possibly stop the air from the
>> crankcase? This leakage must have been there since new.
>>
>>
>

Definitely what I was thinking since he can't get that idle down. Strange!
thanks Jim I don't feel like I am totally losing my mind now! lol



"Jim Behning" > wrote in message
...
> No, your memory is correct. I think there was a metal plug with a hole
> in the middle. So instead of that hose being 13 mm ID it was 3 mm or
> something like that. Just for fun he could get a big C clamp or an
> alligator nose Vise Grip to close off that hose. That would almost
> simulate the missing plug. If the idle drops way down you found one of
> your problems. Once again it could be a lot of problems, not just one.
>
> On Fri, 26 Sep 2008 21:14:05 -0500, "dave AKA vwdoc1"
> > wrote:
>
>>Keep looking! :-)
>>
>>Maybe a restrictor somewhere in that connection, like even on the intake
>>manifold pipe. If that hose has never been changed then all should be
>>good.
>>Maybe I am remembering a water hose instead??????
>>
>>Keep looking! :-)
>>
>>"nutso fasst" > wrote in message
.. .
>>>
>>> "dave AKA vwdoc1" > wrote in message
>>> ...
>>>> You have a vacuum leak or multiple leaks!
>>>> Plug everything to the intake manifold but the throttle body.
>>>> If it still idles high it would have to be the throttle body or intake
>>>> manifold!
>>>
>>> OK, I began checking again. There IS some air leaking into the manifold
>>> through the hose that connects to the valve cover. Completely sealing it
>>> lowers the idle ~100 rpm (still doesn't stop the engine even with idle
>>> air
>>> screw all the way in). I went to a parts store that still had the hose
>>> (049
>>> 103 223 D). The new hose was completely unrestrictive as regards
>>> incoming
>>> air. No point buying it. How could it possibly stop the air from the
>>> crankcase? This leakage must have been there since new.

"Jim Behning" > wrote in message
...
> No, your memory is correct. I think there was a metal plug with a hole
> in the middle. So instead of that hose being 13 mm ID it was 3 mm or
> something like that. Just for fun he could get a big C clamp or an
> alligator nose Vise Grip to close off that hose. That would almost
> simulate the missing plug. If the idle drops way down you found one of
> your problems. Once again it could be a lot of problems, not just one.

I inspected the hose with a strong penlight. The plug with the hole is
there. I felt a plug in the new hose as well, but the old is more
restrictive. I can see light through the small hole but there's apparently
crankcase vapor residue and simply shooting carb cleaner through doesn't
remove it completely. Clearly though, this is 'measured air' that is going
into the manifold, so perhaps the engine can't be shut down with the idle
air screw alone.

Anyway, I'm now back to square 173 and will continue working at it today.
One thought that comes in answer to "how could fixes and cleaning make
things worse?" is the possibility someone screwed the idle screw in too hard
at some point and damaged the seat such that it can't be closed. The crud I
cleaned out was acting as a restriction. I wish I'd looked at that more
carefully when I had the throttle body off.

nf

"dave AKA vwdoc1" > wrote in message
...
> Keep looking! :-)

I checked the AAV (closed when hot). I blocked the intake hose from the AAV
to ensure the AAV was sealing OK. I blocked the hose to the distributor
timing retard and brake booster (thus increasing idle speed because timing
advances quite a bit). I checked the idle air screw for seating using a pen
light and dental mirror (don't see any damage). Throttle butterflies fully
closed. I ran propane around everything again. Opened a vacuum line and
sprayed propane around it just to confirm rpms went up.

From where comes air that burns the fuel to idle fast and blow my cool?

This engine is supposed to be timed with vacuum hoses attached to
distributor. But changing CO changes manifold vacuum which changes timing
which changes idle speed which changes...

(Oops. Slick little wet spot under the car. Never noticed that clutch-side
crank seal leak before.)