TheSamba.com :: View topic - Just failed Emissions- Resolved!

Sat Feb 27, 2010 12:34 pm

Well I just failed CO Emissions testing...grrr so now I head into some unfamiliar territory trying to fix the problems.

Failed on two accounts:

1. High HC Reading- tested at 1176.6 at Idle and 946.2 @ 2500 RPM (Acceptable limit being 1000). I'm reading that this may be caused by unburned or partially burned fuel.

2. High CO readings- 5.57 at Idle and 8.87 @ 2500 RPMs. Acceptable Limit 5.50. This I understand as I am running too rich and could probably try adjusting the mix on the carb.

Are there ways to test these items at home? I will begin my search here on possible solutions to these issues so I can make some adjustments. A little stressed since the bug is a new hobby and I am learning as I go. Part of me says to bring it somewhere but I'd like to learn and make these adjustments myself if possible.

Yesterday I tried to get tested but my RPMS at Idle were too high. I adjusted the idle screw and according to this sheet I am idling @ 1176.6 which I think is still too high. I noticed my amber light flickering today at Idle but with a little gas it would go away. I was probably not warmed up enough when I made this idle adjustment.

My immediate goal is just to get this thing to Pass emissions. I have 60 day temp plates until April so I do have some time to play.

Sat Feb 27, 2010 12:44 pm

I should note that this is a '66. Valves recently adjusted to .006, checked timing and it's at 0 TDC for Distributer # 0231-163-001. Wondering if my timing is off but I'm not seeing this Distrib # anywhere for the proper timing adjustments.

Sat Feb 27, 2010 1:06 pm

Somehow get yourself a good Oxygen Sensor.

It would be best to weld in a threaded adaptor but catching the exhaust gases out of one tail pipes should get you close.

Attach the probe wires to a Voltmeter.

The readings:
0.7V = 13:1 - ideal for HP and exhaust valve cooling
0.3V = 16:1 - you are about to put a massive hole in your pistons!

Also, at wide open throttle you should get 0.8V but if it suddenly drops to 0.5V then your engine is leaning out at high revs (happens particularly with Weber IDFs or Dells)

Obviously Lower Voltage = Leaner mixture.

Its far from perfect, but will give you an idea of what you have without spending much cash.
Hook it up and see what your reading is BEFORE making adjustments. That way you have a fail base line.
Make sure the engine is warmed up.
Adjust the mixture until the voltage drops a tad.

Like I said, rough but cheap.
Also not my idea, but I've done it with a degree of success

Dave

Sat Feb 27, 2010 1:16 pm

move to texas... saftey only inspections for our cars... no inspection at all, if you register as an antique

:P

but seriously... best of luck with it

Sat Feb 27, 2010 1:36 pm

Not sure if moving is the answer but yeah... lol

So looking at the emissions results from Nov 2009 (The PO gave them to me), Umm BIG difference.

At that time is was:

CO- 3.86 Idle and 3.83 at 2500 RPMs
HC- 189 @ Idle, 175 @ 2500 RPMs.

So what the hell happened to this car in a few short months?

I did change plug wires almost immediatly, maybe I need to start there and make sure that I don't have some bad connection.

Sat Feb 27, 2010 2:08 pm

Winter, stuck choke, winter gas mix, jet fell out of carb, points wore and changed the gap which in turn changes the timing, valves out of adjustment, head loosened, plug went bad, plug wire went bad or fell off, dist cap cracked, fuel pressure increased, etc, etc, etc,

dave

Sat Feb 27, 2010 4:03 pm

What carb are you running?

Sat Feb 27, 2010 4:27 pm

An engine this old with technology from 1966 should not be subjected to technical standards and emission levels that conform to questionable goals in 2010.

Whats next, a requirement to install a Catalytic converter?

I have read some posts in the past of people misadjusting the carb to run rich or lean as needed to pass some of these insane tests..you might try a search in the forums for what has been done in the past

Good luck, and I am thankful I live in a state that at least for the present does a reasonable inspection for such an old car..just safety and lights.

Sat Feb 27, 2010 5:53 pm

Asunder wrote: An engine this old with technology from 1966 should not be subjected to technical standards and emission levels that conform to questionable goals in 2010.

Standards when new were something like 4-600 PPM. The present day standard is 50-100% higher than what was required when it was new, so its not that tough a standard. This is still about 100 times more pollution than a modern FI/cat car.

With it rich both at idle and cruise, "adjusting" the carb will not work. You can only adjust idle mixture. Either the engine is burning oil (in which case you are facing a rebuild or exemption before you can pass), or it's running rich due to poor ignition or very wrong jetting. That is why the model of carb matters for what we recommend next. Also, the right distributor may be important, though idle/cruise advance can usually be set to pass if the rest of the motor is right.

Sat Feb 27, 2010 8:08 pm

When I used to go through the joy of testing in Phoenix I would usually retart the timing until it barely ran. This usually satisfied their goofy machines. I actually did put a temporary cat. on my merged system to squeak through with a mild (Scat C45) cam. The best move that I did on my last motor that I built there was to have Pauter grind a performance cam with hardly any overlap. It would go through "most" of the time. I sure miss those days! These smoggy OK skies are so hard to handle.

Sun Feb 28, 2010 5:43 am

Now that I see what everyone goes through, I may never leave NC. Over 30 yrs old, no inspection due. FL I understand has no safety inspections at all.

Sun Feb 28, 2010 5:50 am

Neither does Michigan ;)

Sun Feb 28, 2010 6:03 am

Boyrcr420 wrote: Not sure if moving is the answer but yeah... lol

So looking at the emissions results from Nov 2009 (The PO gave them to me), Umm BIG difference.

At that time is was:

CO- 3.86 Idle and 3.83 at 2500 RPMs
HC- 189 @ Idle, 175 @ 2500 RPMs.

So what the hell happened to this car in a few short months?

I did change plug wires almost immediatly, maybe I need to start there and make sure that I don't have some bad connection.

First, check your point gap, this is subject to wear and will change how the car runs when it does. Look for a little "tit" on the points and file that off if it is there, Adjust it properly and you'll probably find everything returns to as it was status.

It's cheap, it's easy and it could work.

Dave

Sun Feb 28, 2010 7:51 am

ozzmonaut wrote: Now that I see what everyone goes through, I may never leave NC. Over 30 yrs old, no inspection due. FL I understand has no safety inspections at all.

In Tennessee, emissions testing required only on 1975 and later vehicles.

Sun Feb 28, 2010 8:17 am

http://www.thesamba.com/vw/forum/viewtopic.php?t=191105&highlight=failed+emissions

I basically had the same problem and it was as simple as allowing the car to get to proper operating temp.

Sun Feb 28, 2010 8:25 am

Thanks for the replies everyone. I figured that I would do a full tune up and check everything. I will post my carb model later after some coffee :)

So things got a big trickier...

I decided to pull the plugs. 3, 4 looked fine. 2 and 1 were a bit black but not wet or anything. When I was removing #1, it hit a spot coming out where it seized up a little but not bad, it came out fine. (I am always careful not to strip the plugs in the head). Anyways when I took it out at the base it has some thread IN the plug threads and the gasket was sealed to the end of the plug and not loose at all. Well when trying to put the new plug in, it won't thread so I think I have a stripped thread. Joy. Other three went in fine. I spent 2 hours last night trying to thread in the new plug and ofcourse the hardest location (#1).

Today I am going to go try and find a thread chaser, hoping I can clean up the threads and get the new plug in so I can begin the rest of the tuneup and look for other issues.

My carb looks pretty clean but I'll recheck the point gaps, valves, etc etc..

I'm in new spirits today after swearing all night trying to get the new damn plug in. Just hoping a thread chaser works or else I may need to get it towed to my shop.

Sun Feb 28, 2010 8:38 am

Boyrcr420 wrote: .......I decided to pull the plugs............

Just curious, was the engine Hot or Cold??

Dave

Sun Feb 28, 2010 8:43 am

The engine was cold. A roommate was moving so maybe an hour before I moved it from the street into my garage but had previously been sitting for several hours.

I believe someone told me never to remove plugs on a hot engine?

Sun Feb 28, 2010 8:53 am

Boyrcr420 wrote: The engine was cold. A roommate was moving so maybe an hour before I moved it from the street into my garage but had previously been sitting for several hours.

I believe someone told me never to remove plugs on a hot engine?

Yep,
No hard proof, but from my years in the Auto Industry it was felt that removing plugs from Hot ALUMINUM heads is generally a bad idea. (Mercedes, Volvo, BMW, FIAT, Datsun, AMC, Mazda and the all time favorite, Renault.)

It was done in the pursuit of $$$'s though. You don't turn away work because the engine is hot!

Try a thread chaser but put grease on it to catch the little chips, take you time and catch the original threads. If you do there shouldn't be much resistance for you aren't cutting, you are simply reshaping.
Remove it frequently to clean off the grease with chips and apply new. The idea is to keep as many chips as possible out of the cylinder.

Dave

Sun Feb 28, 2010 8:56 am

Best of luck with the #1 plug hole repair. Bummer on that.

Not sure of your distributor. Something like an 0 231 137009 113 905 205K would be suitable for stock '66. This was the vacuum advance dist. used for the German Solex PICT 30-1 carb.

Some of the membership maintain that a difference in altitude requires the carb to be re-jetted. Denver's pretty high up there, isn't it?

But, for the emissions #'s to change like they have over the course of 3 months leads me to think something has gone askew. Keep investigating, but as of now the plug hole repair is top priority. And do report back with what carb is on there.