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Discussion Starter #1
Just bought a 1983 280ZX (not turbo) and am having trouble getting it to pass the Virginia emissions inspection. The NO is within limits, but the HC and CO are not. I've changed the spark plug wires, plugs, cap/rotor, and the exhaust gas sensor; I also checked the timing and it was set at 20 BTDC, but the Haynes manual says it should be 8 +/- 2; so I set it to 10. The sticker under the hood was missing, so I don't know what the specs should be.

- Anybody have any ideas on what to check first?
- What should be the timing and idle RPM specs?

Any help would be greatly appreciated!
 

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Discussion Starter #2
Factory manual says for the N/A model 8 degrees + or - 2. Sounds like your motor was set to the turbo settings which are 24 degrees + - 3.

Idle for 5 speed shold be 700 + -- 100
Automatic 700 rpms + -- 100 with car in drive

Dave
 

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Discussion Starter #3
> Just bought a 1983 280ZX (not turbo) and am
> having trouble getting it to pass the
> Virginia emissions inspection. The NO is
> within limits, but the HC and CO are not.

Sounds like it's running too rich. If it was just HC's then it would likely be the cat converter (if that model has one) But with both the HC's and CO's too high it's probably getting more gas than it can burn properly.
 

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Discussion Starter #4
> Just bought a 1983 280ZX (not turbo) and am
> having trouble getting it to pass the
> Virginia emissions inspection. The NO is
> within limits, but the HC and CO are not.
> I've changed the spark plug wires, plugs,
> cap/rotor, and the exhaust gas sensor; I
> also checked the timing and it was set at 20
> BTDC, but the Haynes manual says it should
> be 8 +/- 2; so I set it to 10. The sticker
> under the hood was missing, so I don't know
> what the specs should be.

> - Anybody have any ideas on what to check
> first?
> - What should be the timing and idle RPM
> specs?

> Any help would be greatly appreciated!

Check the airflow meter. My HC was reading over
21000 HC, the car had a different airflowmeter
so I replaced it with the right kind. It went down to 920 HC. You can try to adjust the airfowmeter you will have to brake the seal.
Check the timing chain to make sure it is correct.
Buy A new cat back, go to a local muffler shop,
it should only cost $100 for a free flow cat.
You will notice it will run better and helps in
passing emissions.
 
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