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HOLLAATYABOYY1

Failed Emissions

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1976 datsun 280z.  Not in Cali needs to pass an idle test.   

 

Did this year 280 come with a cat? They wrote on my fail sheet no cat and no muffelor .  But I was under the assumption I didn’t need a cat (will install muffelor ) 

 

Looks like I failed O2 by a little bit.    drove the car 20-30 mins to inspection station.  Filled with 93 octane.   I know I have a bad air regulator( can change but am told that’s only for cold start).    new spark plugs    / old oil , old wires, old filters.    I just need to get this thing to pass and then I will be doing a motor swap so I don’t want to sink in a lot of money.    Can anyone help me out 

 

 

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I believe so, they call the hump on the drivers side the cat hump because of that if I remember correctly.

 

The CO% is carbon monoxide and a catalytic converter's job is to convert that into CO2, so without one you would have to do some funny business to pass. 

 

Edit: I am wrong and I am one of the "confused guys" NewZed mentions, lol. Look below for good answers.

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My Federal 1978 280Z did not come with a catalytic converter.  Judging by the limits you posted, it looks like your state uses the Federal emissions standard, and that should be able to pass without a converter.  It looks like your test station has incorrect information - yes the California 280Zs came with converters, I think they were added along with fuel injection to meet higher CA standards.

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5 minutes ago, SleeperZ said:

My Federal 1978 280Z did not come with a catalytic converter.  Judging by the limits you posted, it looks like your state uses the Federal emissions standard, and that should be able to pass without a converter.  It looks like your test station has incorrect information - yes the California 280Zs came with converters, I think they were added along with fuel injection to meet higher CA standards.

Delaware is horrible no one knows anything.  I’m going to have to argue that one out wih them.   Do you have any way you can help me pass the co2 test without dropping a bunch of money into it ?

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1 hour ago, HOLLAATYABOYY1 said:

1976 datsun 280z.  Not in Cali needs to pass an idle test.   

 

Did this year 280 come with a cat? They wrote on my fail sheet no cat and no muffelor .  But I was under the assumption I didn’t need a cat (will install muffelor ) 

 

 

There should be a big silver sticker on the driver's side door jamb that says either Catalyst or No Catalyst.  Sometimes the guys get confused when they see the spot for it underneath  or they just assume that all cars have converters.  The sticker is what matters though, make sure to point out that it says NO catalyst.  Unless the car started in CA then you need to put it back on.  Federal law, no tampering.

 

If I recall correctly, high CO is due to incomplete combustion.  Your hydrocarbon levels are under though so you're not far off.  You can probably get there by opening up the idle air bypass screw on the side of the AFM, under the rubber plug.  Turning it outward lets more air past the AFM vane, leaning out the idle mixture.

 

Also, set your timing to spec.  If it's too far advanced you can get misses, that will cause problems.

 

 

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Posted (edited)
32 minutes ago, Neverdone said:

large101990.jpg

 

This is the sticker he's talking about. It's on the underside of the hood. If your car doesn't have one, you can literally by one from MSA for 25 dollars.

There’s one problem fixed  I know it’s off topic.   But do you guys have any info on troubleshoitingvthe parking loghts(side markers ) 

Edited by HOLLAATYABOYY1

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1 hour ago, NewZed said:

 

There should be a big silver sticker on the driver's side door jamb that says either Catalyst or No Catalyst.  Sometimes the guys get confused when they see the spot for it underneath  or they just assume that all cars have converters.  The sticker is what matters though, make sure to point out that it says NO catalyst.  Unless the car started in CA then you need to put it back on.  Federal law, no tampering.

 

If I recall correctly, high CO is due to incomplete combustion.  Your hydrocarbon levels are under though so you're not far off.  You can probably get there by opening up the idle air bypass screw on the side of the AFM, under the rubber plug.  Turning it outward lets more air past the AFM vane, leaning out the idle mixture.

 

Also, set your timing to spec.  If it's too far advanced you can get misses, that will cause problems.

 

 

Any idea how much to adjust it outward ?

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3 hours ago, HOLLAATYABOYY1 said:

Any idea how much to adjust it outward ?

If I don't pass I adjust it outward until I hear the engine stumble a bit then run it back in a turn.  You're supposed to use a gas analyzer.  In Oregon we get unlimited tries, so, one or two passes and you're done.

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4 hours ago, Neverdone said:

large101990.jpg

 

This is the sticker he's talking about. It's on the underside of the hood. If your car doesn't have one, you can literally by one from MSA for 25 dollars.

  There are two of them.

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6 hours ago, NewZed said:

If I don't pass I adjust it outward until I hear the engine stumble a bit then run it back in a turn.  You're supposed to use a gas analyzer.  In Oregon we get unlimited tries, so, one or two passes and you're done.  

 

Do you do that before you leave your house going to get inspected or once you are there and fail 

 

 

 

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On 4/5/2018 at 1:46 PM, HOLLAATYABOYY1 said:

  I know I have a bad air regulator( can change but am told that’s only for cold start).    

 

If your air regulator is bad, the vane never closes and you'll always get bypass air into the manifold.  A couple of minutes after start the vane would normally be closed and there would be no bypass air (if it was working properly).  IDK if that will help your emissions but I'd block off one of the hoses if I wasn't inclined to make it work the way it should...

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cg, I think that you're mixing the throttle blade bypass (the AAR) with the AFM vane bypass (the screw in the AFM).  The first just raises the idle speed, the second doesn't change idle speed directly but it does change the air'fuel ratio, by letting air past the AFM vane.

 

I didn't answer the last question because it's kind of like asking if you should part your hair on the right or on the left.  Doesn't matter where, you still have to get through the test.

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On 4/5/2018 at 11:16 PM, NewZed said:

If I don't pass I adjust it outward until I hear the engine stumble a bit then run it back in a turn.  You're supposed to use a gas analyzer.  In Oregon we get unlimited tries, so, one or two passes and you're done.

 

Hows it going guys can you tel me what screw I’m supposed to be adjusting ? 

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I’m trying to spend as little as possible for it to pass inspection because I’m ripping the drivetrain out 

 

i have turned the screw out until the engine sputtered and died.  It took a few quarter turns for her to start and stay running and I left it like that .....

 

is there anything else else I can do to insure that I pass my co2?  Octane booster? Which kind? 

 

Also a known problem i and the orevious owner had was backfiring.  If you hold the throttle at a constant 2-3k rpm and let go you will get a nice size exhaust backfire.    Will this effect co2.   Is there anything I can do that’s free to look at this (besides testing coil) 

 

thanks 

Edited by HOLLAATYABOYY1

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