Failed Smog But not by much please Help!!

[sr20garcia]

I have a 1993 Nissan 240 completely stock. I cant seem to get to pass smog but I am getting a lot closer. The car registered below max levels in each category of the smog test except in HC. I searched and couldnt find much information on how to reduce HC levels.

At 15MPH it measured 71 HC and the MAX allowed is 68 HC
AT 25MPH it measured 40 HC and the MAX is 39 HC

Those it just need a slight tweek somewhere?? I am so close to getting it to pass ANY IDEAS???

Thanks in Advance.

[zer0c123]

google and try the denatured alcohol trick. You can get the stuff at the paint section of home depot or lowes. That should be able to help you pass HC and CO. After you pass you might wanna consider later diagnosing the actual problem, but then we all got stuff to do...

[Klits562]

Hydrocarbons are unburnt fuel so make sure your timing is perfect, also check your ignition system, maybe new plugs wires dizzy cap stuff like that.
Also if you dont have a thermostat put one in, since the lower the engine temp the higher HC tend to be.

[the converted]

What are the rest of your numbers like? It's how they interact with each other that helps tell you what you need to do. But most likely, your timing is retarded.