81 Scirocco smog check fixes update

Installed new plug wires and distributor cap... tested vacuum
retard/advance... cleaned crud-encrusted injectors and tested for good spray
pattern... installed new injector o-rings and buckets... checked cold start
valve for leakage... removed and thoroughly cleaned throttle body...
installed new o-ring on idle screw... sealed vacuum leak in plastic intake
tube... replaced cracked-and-sealed-with-electrical-tape 'connector hose'
between plastic intake tube and throttle body... installed new O2 sensor.

Engine now seems to run OK but idle's a problem. With idle screw turned
almost all the way in I can barely get down below 1K rpm by adjusting the CO
screw lean. But then, when I do the dwell meter CO test per
http://vintagewatercooleds.com/tech/...issions/emissi
ons.htm
the dwell is over 85 - supposedly way too lean. But manifold vacuum is about
18" hg, higher than the maximum of 16" recommended in the Clymer manual. The
least dwell I get by enriching CO is about 52 (and it doesn't fluxuate
much), but at that point the idle is above 1500 and manifold vacuum is above
20".

I just removed the old Emico CAT. Can still see through screens but exhaust
pipe upstream and down is caked with carbon!

Tomorrow I check timing again...could all the vacuum leaks being sealed have
altered it? Will also install new Bosal CAT (jeez, what sloppy welds!).

Concerned about engine noise. Quiet enough at idle but when I open the
throttle there's a hell of a rattling noise. I'm wondering if the timing
belt tensioner is going bad. It's possible it has over 150K miles on it.

nf

Probably excess air is getting into the intake manifold.
Check for problems like a leaking brake booster, vacuum leaks around the
throttle body, throttle plates not fully seating, ign timing way too
advanced, leak in Aux Air Valve, or something else allowing this air in!
You must solve any leaks and high idling before adjusting that CO!


"nutso fasst" > wrote in message
...
> Installed new plug wires and distributor cap... tested vacuum
> retard/advance... cleaned crud-encrusted injectors and tested for good
> spray
> pattern... installed new injector o-rings and buckets... checked cold
> start
> valve for leakage... removed and thoroughly cleaned throttle body...
> installed new o-ring on idle screw... sealed vacuum leak in plastic intake
> tube... replaced cracked-and-sealed-with-electrical-tape 'connector hose'
> between plastic intake tube and throttle body... installed new O2 sensor.
>
> Engine now seems to run OK but idle's a problem. With idle screw turned
> almost all the way in I can barely get down below 1K rpm by adjusting the
> CO
> screw lean. But then, when I do the dwell meter CO test per
> http://vintagewatercooleds.com/tech/...issions/emissi
> ons.htm
> the dwell is over 85 - supposedly way too lean. But manifold vacuum is
> about
> 18" hg, higher than the maximum of 16" recommended in the Clymer manual.
> The
> least dwell I get by enriching CO is about 52 (and it doesn't fluxuate
> much), but at that point the idle is above 1500 and manifold vacuum is
> above
> 20".
>
> I just removed the old Emico CAT. Can still see through screens but
> exhaust
> pipe upstream and down is caked with carbon!
>
> Tomorrow I check timing again...could all the vacuum leaks being sealed
> have
> altered it? Will also install new Bosal CAT (jeez, what sloppy welds!).
>
> Concerned about engine noise. Quiet enough at idle but when I open the
> throttle there's a hell of a rattling noise. I'm wondering if the timing
> belt tensioner is going bad. It's possible it has over 150K miles on it.
>
> nf
>
>

"dave AKA vwdoc1" > wrote in message
...
> Probably excess air is getting into the intake manifold.
> Check for problems like a leaking brake booster, vacuum leaks around the
> throttle body, throttle plates not fully seating, ign timing way too
> advanced, leak in Aux Air Valve, or something else allowing this air in!
> You must solve any leaks and high idling before adjusting that CO!

Thanks, I'll keep looking. Very frustrating. Maybe all the crud should've
been left in place.

85 is probably really 44. I had to do math when I worked on my 84. it
was either x/2 or 2x. It has been over 6 years since I did the dwell
CO on that car.

Dave has the excess air leaks covered. I question electrical tape
around vacuum leaks.

Replace timing belt and tensioner.

On Mon, 22 Sep 2008 22:16:07 -0500, "dave AKA vwdoc1"
> wrote:

>Probably excess air is getting into the intake manifold.
>Check for problems like a leaking brake booster, vacuum leaks around the
>throttle body, throttle plates not fully seating, ign timing way too
>advanced, leak in Aux Air Valve, or something else allowing this air in!
>You must solve any leaks and high idling before adjusting that CO!
>
>
>"nutso fasst" > wrote in message
...
>> Installed new plug wires and distributor cap... tested vacuum
>> retard/advance... cleaned crud-encrusted injectors and tested for good
>> spray
>> pattern... installed new injector o-rings and buckets... checked cold
>> start
>> valve for leakage... removed and thoroughly cleaned throttle body...
>> installed new o-ring on idle screw... sealed vacuum leak in plastic intake
>> tube... replaced cracked-and-sealed-with-electrical-tape 'connector hose'
>> between plastic intake tube and throttle body... installed new O2 sensor.
>>
>> Engine now seems to run OK but idle's a problem. With idle screw turned
>> almost all the way in I can barely get down below 1K rpm by adjusting the
>> CO
>> screw lean. But then, when I do the dwell meter CO test per
>> http://vintagewatercooleds.com/tech/...issions/emissi
>> ons.htm
>> the dwell is over 85 - supposedly way too lean. But manifold vacuum is
>> about
>> 18" hg, higher than the maximum of 16" recommended in the Clymer manual.
>> The
>> least dwell I get by enriching CO is about 52 (and it doesn't fluxuate
>> much), but at that point the idle is above 1500 and manifold vacuum is
>> above
>> 20".
>>
>> I just removed the old Emico CAT. Can still see through screens but
>> exhaust
>> pipe upstream and down is caked with carbon!
>>
>> Tomorrow I check timing again...could all the vacuum leaks being sealed
>> have
>> altered it? Will also install new Bosal CAT (jeez, what sloppy welds!).
>>
>> Concerned about engine noise. Quiet enough at idle but when I open the
>> throttle there's a hell of a rattling noise. I'm wondering if the timing
>> belt tensioner is going bad. It's possible it has over 150K miles on it.
>>
>> nf
>>
>>
>

nutso fasst wrote:
> Installed new plug wires and distributor cap... tested vacuum
> retard/advance... cleaned crud-encrusted injectors and tested for good spray
> pattern... installed new injector o-rings and buckets... checked cold start
> valve for leakage... removed and thoroughly cleaned throttle body...
> installed new o-ring on idle screw... sealed vacuum leak in plastic intake
> tube... replaced cracked-and-sealed-with-electrical-tape 'connector hose'
> between plastic intake tube and throttle body... installed new O2 sensor.
>
> Engine now seems to run OK but idle's a problem. With idle screw turned
> almost all the way in I can barely get down below 1K rpm by adjusting the CO
> screw lean. But then, when I do the dwell meter CO test per
> http://vintagewatercooleds.com/tech/...issions/emissi
> ons.htm
> the dwell is over 85 - supposedly way too lean. But manifold vacuum is about
> 18" hg, higher than the maximum of 16" recommended in the Clymer manual. The
> least dwell I get by enriching CO is about 52 (and it doesn't fluxuate
> much), but at that point the idle is above 1500 and manifold vacuum is above
> 20".

What happens if you disconnect and plug the auxiliary air valve? 1K is
too high you should be able to get it down around 800 or so. In fact
you should be able to stall the engine by turning the idle screw in,
assuming it's the same as my old '84 GTI.

(diversion)

once upon a time, I did a "tuneup" myself on said GTI. Ran fine, except
a short while after said tuneup I found that the car would tend to
stall if I was in traffic and quickly shut the throttle and depressed
the clutch at the same time. I put up with this for maybe a month or so
until I got annoyed one day as I was stuck on I-66 and got sick of
needing three feet (and having the car stall a couple times.) I pulled
over, popped the hood, and backed the idle screw out a little. Idle
went up to about 1000 RPM. Same thing happened. I pulled over again,
bumped the idle up a little more, same thing. I pulled over, backed the
screw out some more, idle got up to about 1300 RPM, I heard a "click"
from the AAV and suddenly the idle was back down around 7-800. D'oh! I
had screwed the idle screw in way too far and the AAV was wide open at
idle keeping the engine from stalling. Once I readjusted the idle to
spec with the AAV *closed* I never had another problem with it (well,
until the alternator died, I found the allen head screw under the timing
cover stripped, and I sold it to a guy in Rockville after buying a nicer
Scirocco for about the cost of having the alternator replaced.)

> I just removed the old Emico CAT. Can still see through screens but exhaust
> pipe upstream and down is caked with carbon!
>
> Tomorrow I check timing again...could all the vacuum leaks being sealed have
> altered it? Will also install new Bosal CAT (jeez, what sloppy welds!).

Sounds to me like you still have air bypassing the throttle body, if you
can't adjust the idle down far enough.

> Concerned about engine noise. Quiet enough at idle but when I open the
> throttle there's a hell of a rattling noise. I'm wondering if the timing
> belt tensioner is going bad. It's possible it has over 150K miles on it.

Definitely check it out. An 8V shouldn't bend valves if it breaks, but
Murphy says if you end up walking it's going to be at the most
inconvenient time.

Or, I'll be happy to take this POS off your hands (hey, the girlie
needs a new car, and I've always had a thing for first-series roccets.)

nate

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

"Nate Nagel" > wrote in message
...
> What happens if you disconnect and plug the auxiliary air valve? 1K is
> too high you should be able to get it down around 800 or so. In fact
> you should be able to stall the engine by turning the idle screw in,
> assuming it's the same as my old '84 GTI.

Thanks for reply.

I discovered the boot over the air flow sensor is leaky. Hope that's the
culprit.

Aux air valve is only a few K miles old. I tried squeezing the hose and got
no change in RPM.

Interesting experience with the idle screw and AAV. I'll try backing the
screw way out if high idle persists after the boot is replaced.

"Jim Behning" > wrote in message
...
> 85 is probably really 44. I had to do math when I worked on my 84. it
> was either x/2 or 2x. It has been over 6 years since I did the dwell
> CO on that car.

Dwell meter was reading 43 in the 8 cyl range. I'm supposed to double that
for 4 cyl. The lowest reading I could get was 26 (x 2 = 52).

Using your non-plastic-dissolving propane gas method, I found vacuum leaks
around the rubber boot atop the air flow sensor. The boot looks OK but won't
seal. I found a new one and will pick up and install tomorrow. Thanks for
that tip!

For the sake of Googling Posterity I'll expound on cleaning injectors...

I did not use a puller. I clamped injectors with vise grips and levered them
out with a very large screwdriver using rag-covered valve cover as pivot
point. Injectors #1-#3 popped out cleanly, but #4 came out with bucket
attached. I levered the bucket off using a box-end wrench and screwdriver.
The old o-rings had turned into hard plastic, but snipping them with
miniature wire cutters easily cracked them open. I cleaned the outside of
the injectors with spray carb cleaner and rags, using Q-tips on the ends.
Plastic buckets were not broken but threads were deteriorated so all were
replaced. I cleaned the injector holes with Q-tips soaked in carb cleaner
and blew them out with compressed air. I lightly applied Hylomar HPF to the
new bucket threads. A 12mm hex socket was used to remove/install buckets.
Injector o-rings were soaked in kerosene prior to sliding them on. Injectors
popped in pretty easily. Subsequent vacuum test with propane gave no
indication of any leakage.

> "dave AKA vwdoc1" > wrote in message
> ...
> > Probably excess air is getting into the intake manifold.
> > Check for problems like a leaking brake booster, vacuum leaks around the
> > throttle body, throttle plates not fully seating, ign timing way too
> > advanced, leak in Aux Air Valve, or something else allowing this air in!
> > You must solve any leaks and high idling before adjusting that CO!

ARG! I fixed the only leak I found - around the intake boot. Bypassed brake
booster and windshield washer with vacuum line to distributor. Set timing to
3 ATC. NO significant change.

Leaky injector seals and a cracked intake tube are now fixed, and yet the
engine now idles worse than before. Idle screw all the way in and CO way
lean to get down to 1K. Driving around the neighborhood car seems to run
great. Lugging it doesn't produce any ping. But with stop and go driving
it's running on the hot side of normal, and when I checked a couple of plugs
they were squeeky clean with white insulators.

I checked the throttle plates when I had the throttle body off and they
looked fully closed (of course, there was a bit more clearance all the way
around them after cleaning). I don't understand how there could be
significant leakage into the intake manifold. At idle, there is 16" HG in
the hose that goes from the manifold to the distributor vacuum retard. There
is 0" in the hose that goes from the back of the throttle body to the
distributor vacuum advance.

OK just say the idle is higher. When I hear worse I think of a rough &
shaking engine that is about to stall/die.

What did you do to the windshield washer again?

Are you sure the vacuum unit is not leaking and is working?
I have had to free up the innards of a lot of distributors since most don't
get oiled in their centers.
Also the plates moved by the advance unit sometimes moves stiffly.

Oh I call this progress since all that you are doing/repairing creates
changes! ;-)
Now make sure that the throttle plates are fully closing. The stop screw
stops the primary plate from jambing in the throttle bore.
See if you can allow the throttle to close more.

Is there an EGR system?

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?
Been too long since I have worked on a VW of your vintage. <:-)
--
later,
(One out of many daves) & running out of ideas! lol

"nutso fasst" > wrote in message
...
>> "dave AKA vwdoc1" > wrote in message
>> ...
>> > Probably excess air is getting into the intake manifold.
>> > Check for problems like a leaking brake booster, vacuum leaks around
>> > the
>> > throttle body, throttle plates not fully seating, ign timing way too
>> > advanced, leak in Aux Air Valve, or something else allowing this air
>> > in!
>> > You must solve any leaks and high idling before adjusting that CO!
>
> ARG! I fixed the only leak I found - around the intake boot. Bypassed
> brake
> booster and windshield washer with vacuum line to distributor. Set timing
> to
> 3 ATC. NO significant change.
>
> Leaky injector seals and a cracked intake tube are now fixed, and yet the
> engine now idles worse than before. Idle screw all the way in and CO way
> lean to get down to 1K. Driving around the neighborhood car seems to run
> great. Lugging it doesn't produce any ping. But with stop and go driving
> it's running on the hot side of normal, and when I checked a couple of
> plugs
> they were squeeky clean with white insulators.
>
> I checked the throttle plates when I had the throttle body off and they
> looked fully closed (of course, there was a bit more clearance all the way
> around them after cleaning). I don't understand how there could be
> significant leakage into the intake manifold. At idle, there is 16" HG in
> the hose that goes from the manifold to the distributor vacuum retard.
> There
> is 0" in the hose that goes from the back of the throttle body to the
> distributor vacuum advance.
>
>