80 Westy vs. California Smog Test

[vanagonliebe]

took my van in for a smog inspection and the man failed her as a gross polluter. It passed everything but the CO output at idle, giving a reading of 471 when 220 I believe was the max. I'm told this is due to a rich fuel/air mixture. The O2 sensor is fairly new so not sure what is causing the fail.
She has a recently rebuilt engine and from what I've read thinking it might be:

-The idle mixture screw adjustment
-advanced timing
-bad catalytic converter.

My knowledge is limited when it comes to these things so if you have any insight it would be much appreciated.

[reluctantartist]

Double check the oxygen sensor to make sure it is not faulty and is hooked up correctly. If you redid the vacuum hoses then your Air Fuel Mixture is probably off.
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1982 Westy, 1974 412 Variant... Yes, Aircooled's are great! Oh and I do have modern computer controlled vehicles too, but I just don't care about them.

[vanagonliebe]

O2 sensor is covered in dark black residue but from my test seems to be working correctly. The residue I believe is due to a rich mixture, still not sure how to correct this though.

[reluctantartist]

Your o2 should read around 4.5 volts (it fluctuates so you have to average the reading) when the engine is warm and at idle with the digital idle stabilizer plugs connected together and your idle speed set around 900-950 rpm. You need to blip the idle first and make sure the engine is warm ie oil temp of >140. I prefer an oil temp of 180 for checking. If o2 voltage is a lot higher then your idle mixture is too high so you need to back off on the A/F mixture screw to let in more air. Many times the screw is all the way in because it was being used to compensate for a vacuum leak. Is there carbon soot on the tail pipe? Your o2 sensor may be fouled too now so make sure it is fluctuating on the voltage reading.
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1982 Westy, 1974 412 Variant... Yes, Aircooled's are great! Oh and I do have modern computer controlled vehicles too, but I just don't care about them.

[vanagonliebe]

Thanks for the help reluctant.

I ran her to 180 F and tested the O2 sensor output, the reading I was getting was .450 V and fluctuating so I swapped out the O2 sensor (only 20 bucks). The output of the new O2 was now .915 V (fluctuating). So started messing with the air/fuel screw and was able to get it down the .845 V or so but it wouldn't go any lower...

It was only failing CO output at idle and not sure what else would cause this... any ideas?

thanks again all

[70coupyel]

On my 73 bus(carbs) I failed but the smog guy knew VWs. He told me that I need to re torque my head bolts. I think the hydrocarbons was high. Did that and all was good. This might not apply to FI.
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[vanagonliebe]

Thanks for the tip.

It actually passed like a champ when it came to the HC and was even good on the 2500RPM CO test... just idling too rich for the CO at idle RPM test. I ran it cold monitoring the O2 sensor readings, they stay around .450 V until it reaches 180 degrees then the readings go all the way up to 1.3 V!!! Thinking I may just take her in cold and she if she will pass, wish I had my own exhaust sniffer to work with. Was thinking about getting a Carbon Monoxide detector from home depot and trying to rig up a way to read the exhaust CO output...

[reluctantartist]

You might want to check the temp 2 switch. The oxy sensor will give you a close approximation of CO. When you do this you need to make sure you are at the right idle ~945 rpm with the idle stabilizer plugs connected together and the timing is at 5 degrees ATC. And of course the engine needs to be warm. You should rev it up to 3k rpms to get the oxy senser hot and then look at it's voltage.
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1982 Westy, 1974 412 Variant... Yes, Aircooled's are great! Oh and I do have modern computer controlled vehicles too, but I just don't care about them.

[vanagonliebe]

Was checking out what I think is the temp sensor last night, if I'm correct it is located just to the right of cylinder #3. The sensor doesn't appear to be wired to anything the lead and ground are simply connected together. Thinking the guy who rebuilt it may not have seen a need for it...?

[vanagonliebe]

Ok, think I found it to the left of the spark plug. The resistance was fine, 147 ohms at 180 degrees, and it put out 0.450 V at 120 degrees and dropped to 0.200 at 180 degrees. Not sure if the voltage is correct or not

[reluctantartist]

Replace it. It is like $20.
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1982 Westy, 1974 412 Variant... Yes, Aircooled's are great! Oh and I do have modern computer controlled vehicles too, but I just don't care about them.

[vanagonliebe]

Right on, got a new TS2 on the way.

Finally got my timing gun to work today as it hasn't wanted to put out any light up to now. My timing scale is missing off the engine so I had to use pictures and count lines off the fan cover screen to see where I was at. Looks like she was timed around 25 degrees ATC. I moved it back to around 5 degrees ATC which increased the engine idle quite a bit. From here I adjusted the idle screw on the throttle body to return idle to 900 RPM after which my Oxygen sensor was reading more aound the .5 to .6 V range.

Just wanted to make sure I did the right thing here, 25 degrees ATC doesn't seem right to me but I purchased the van from a VW mechanic three months ago, after a full rebuild, so would have thought he already had things dialed in pretty well...

The red is where the timing was before I adjusted, I marked TDC from counting fan cover slits and comparing to the photo in the manual.

[reluctantartist]

If you were fooling around with things in there the timing may have changed. Also I am not too keen on relying on the "vw mechanic". These are older vehicles which require a different knowledge than working with a new car. For instance vw mechanics seem to fail to realize that all the rubber is suspect when checking for vacuum leaks and often times do bandaid procedures to make the car run right. Also check the threads on sealing the engine compartment now that you are getting this running correctly. Many "Vw mechanics" are cavalier about sealing the compartment; some even think it is OK to run without the thermostat or even it is OK if the engine compartment seal is missing. You will be your own best mechanic in the end. There are true VW guru mechanics (especially air-cooled) out there...but they are far and few.
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1982 Westy, 1974 412 Variant... Yes, Aircooled's are great! Oh and I do have modern computer controlled vehicles too, but I just don't care about them.

[vanagonliebe]

Swapped out the O2 Sensor, TSII and adjusted the timing and took her back to the smog shop for second run. I was able to reduce the CO output at idle from 4.37% down to 3.35% but still not the 2.00% california demands. He also failed my EGR and ignition timing as well.

I'm also hearing air flow around the air distributor box, I've replaced all the vacuum lines so assumed it was just the air flow through the box, could it be that I have a leak in the underside of my distributor box...?

[reluctantartist]

Chances are your S-boot is cracked creating a vacuum leak. Do you have the Bentley manual? You do not have an EGR on a 1980 vanagon so there is nothing to fail. Was your idle stabilizer reconnected?
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1982 Westy, 1974 412 Variant... Yes, Aircooled's are great! Oh and I do have modern computer controlled vehicles too, but I just don't care about them.

[vanagonliebe]

Gave the S-boot a second look over and no cracks. The bonding points on the intake air distribution box were separating and put off bubbles when sprayed with starter fluid(green in picture). I crimped the bonding flanges back together with some pliers and this eliminated most of my leaking air noise (I believe the rest is coming from the underside bonding). I'm going to remove it tomorrow and try and seal the whole thing up proper with some jb-weld.

The idle stabilizer is nowhere to be found(thinking it was eliminated during rebuild along with the thermostat). Thought this was the EGR in the photo. Also did some research on the distributor #'s and found it is off a 73 bus, not sure what this means for my timing.

Took some breaks from the engine and worked on the inside: lined the cabinets with carpeting, added a whiteboard above the engine compartment so I can do some drawing while I'm laying down, painted the side panels with some granite textured enamel and installed my newly reupholstered seats. Can't wait to get her running right so we can take a trip to big sur

[reluctantartist]

What year is your vanagon? The 1980 cal model did not have an egr. The 81-83 did. Since you do have an EGR you need to look at the EGR filter. They rust out and cause major vacuum leaks. The OXY reading should be .45-.5 volts at idle with the digital idle stabilizer plugs connected together not to the stabilizer and an idle of about 940. The digital idle stabilizer is on the side:

Remember to reconnect the idle stabilizer after adjusting the A/F mixture. But first make sure the EGR filter is not rusted out.
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1982 Westy, 1974 412 Variant... Yes, Aircooled's are great! Oh and I do have modern computer controlled vehicles too, but I just don't care about them.

[reluctantartist]

Also do not mess with the idle stabilizer plugs with the engine running!
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1982 Westy, 1974 412 Variant... Yes, Aircooled's are great! Oh and I do have modern computer controlled vehicles too, but I just don't care about them.

[vanagonliebe]

Has a new EGR filter and idle stabilizer isn't anywhere to be founnd. Is it imperative that I have an idle stabilizer?
Did manage to get the O2 readings down to around .550-.600V with the new O2 sensor, timing, plugs and TSII sensor but still not quite there. Is it possible that my leak in the air distributor box is causing it to run rich at idle? I'm thinking that I am loosing air after the AFM, thus the engine is getting less air than it thinks it is getting... is this a reasonable deduction?

[reluctantartist]

If you do not have a digital idle stabilizer then you should get one. Look for the plugs they are probably plugged together because the stabilizer failed and was not replaced. Can you get a bigger picture of your engine compartment? You mentioned having the wrong distributor as well I am wondering how much your fuel injection has been tampered with.
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1982 Westy, 1974 412 Variant... Yes, Aircooled's are great! Oh and I do have modern computer controlled vehicles too, but I just don't care about them.