77 FI bus can't pass smog in CA (what's new, amirite?)

[tvargs]

I am *this close* to getting the bus passed smog - I can taste it. No, really: I licked it. (kidding.)

I think that it's running super lean, but want to check with the more experienced folks to make sure I'm not missing anything crucial from the latest test results:
[album]211[/album]

HC and CO are way under (which is partially on purpose because I originally failed - gross polluter failed - when I unknowlingly took it to be smogged after buying it, foolishly trusting the PO who claimed it would pass smog "no problem" and ended up with CO around 8%), but I miss pretty big on NO.

Haven't made my way through Colin's in depth AFM adjustment process (and now it will be updated??), but am I even right to think that richening the mixture will lead to lower NO? I highway (280 from SF and back) drove it for an hour before pulling into the test-only station, every small thing is new (rotor, cap, plugs, wires), and the longblock is a <200 mile rebuild by Adrian from Headflow Masters (who is a major hero in my eyes - story for another time).

I would love to hear your thoughts - it's been a frustrating process and I'd love to get this baby street legal before my first kid is born next month!

[vwlover77]

NOx is a tradeoff with CO. A very lean mixture will result in high NOx. Curiosity question: Is your EGR system fully operational? Its purpose is to lower NOx at speed.

It seems that you have some room to enrich the mixture to bring down the NOx number. This can be done by turning the big toothed wheel inside the AFM a few teeth in the counter-clockwise direction. But without an exhaust analyzer or at least an LM1 to help you, it's a guessing game how much you should adjust it to pass the test.

Do you have a way to check it before you pay for another test???

[Lanval]

FWIW,

in CA it's state law that a seller must provide a current (last 90 days, I believe) smog cert. for any used car that is sold. This means the seller is on the hook for getting it smogged. Probably requires at least the threat of the a lawyer at this point, but if you want the PO to pay (or take the VW back and return the money) the law is on your side.

Best,

Mike

[tvargs]

@vwlover77 - I've got an LM-1, so I'll make an attempt tomorrow to richen the mixture. Unfortunately, I can't test NOx with the LM-1 so there's still a chance that it will be high before retesting, even with a richer mixture (might suggest a busted cat). That being said, the guy at the smog spot (Richie's Test-Only on 14th and Mission, SF) is really nice and has basically been letting me come in and pre-test for $20 bucks. Those $20 bucks have added up over time but it's better than failing multiple times, officially!

I don't know about the EGR - I'll add that to my list of to-dos for tomorrow, and report back.

@Mike - you are totally right, bummer that I didn't know that (or do the necessary research) before I bought it last June. The PO also sold me the van without letting me know that cylinder 3 was leaking 80%, and Adrian told me it was not even a usable core - all things I should have known/tested before handing over my money. Here I am, living and learning. It's really close to passing - and I think maybe a little bit of tweaking might get it done!

[vwlover77]

Check out the graph below.

If you can set your AFR as measured by the LM-1 to 14.0 at 25mph (what gear are they using?), you might have a shot at passing.

An AFR of 14.0 is is 1.3% CO which is below the lowest max allowable of 1.46% at 25mph from the test printout.

That should get your NOx on the lower part of the curve to the left of the vertical line, and hopefully keep your HC under the limit too.

Good luck!