Need help, failed smog - hydrocarbons too high

[A17Z]

I barely failed -
Hydrocarbons (HC)
MAX AVE MEAS
58 9 61 <------ 3 points too high! 15 mph
42 7 42 <------ at the max, just passed! 25 mph

I've been told that high HCs means there is too much unburned fuel. How do I reduce this!?

Before the test I already replaced the spark plugs, dist. cap and rotor and fuel filter. Oil was replaced recently about 1500 miles ago. Ran 91 octane. Drove the car for 30 minutes to the shop.

Last year when I smogged I had similar HC readings but I did acutally pass. So i'm thinking there has been a problem since then and it's bigger than the standard routine maintenance. Oh yeah I have a stock 98 S14 w/ KA.

What else can I do to get the hydrocarbons down?

[the head]

run low octane gas it burns faster and therefore more completely than high octane

odds are VERY GOOD you will drop three points and it is free and requires no time

[idlafie]

Originally Posted by A17Z

I barely failed -
Hydrocarbons (HC)
MAX AVE MEAS
58 9 61 <------ 3 points too high! 15 mph
42 7 42 <------ at the max, just passed! 25 mph

I've been told that high HCs means there is too much unburned fuel. How do I reduce this!?

Last year when I smogged I had similar HC readings but I did acutally pass. So i'm thinking there has been a problem since then and it's bigger than the standard routine maintenance.

What else can I do to get the hydrocarbons down?

Sound like you're running too rich!! Change or clean your air filter, (if you already haven't), disconnect & clean out your IAV valve, (if you already haven't), then recheck your timing & idle. SOHC motors are 15 degrees and DOHC motors are 20 degrees if I recall correctly. Once you've cleaned out your IAV valve, reconnect it, then check your idle. Disconnect the three wire sub-harness, (black, white, green??) that runs right next to the throttle body by the engine coolant temperature sensor wires. Connect a tachometer to the motor, put your transmission in neutral, start the motor & set your idle to 650 RPM. Use the Idle Adjusting screw that's hidden on the lower part of the passenger side of the motor to adjust your idle. Once you get your idle down to 650 RPM then reconnect the subharness back up. Your idle shouldn't change more than 50 rpm from the 650 you set it at.
Make sure to check you have a GOOD CLEAN electrical connection at the Engine Coolant Temperature Sensor wire. If you wiggle that wire and your idle starts to fluctuate, then you need to disconnect it, clean it, grease it with di-electric grease, then re-connect it. A bad signal from the engine coolant temperature sensor wire will cause extra fuel to dump into your intake manifold causing you to run rich. I see this all the time on S13's, (sometimes on S14's too!!)
Also, check the small rubber line that runs from the BPT valve to the EGR. That little rubber line cracks from all the heat your engine puts out & can cause you to fail smog for too much NO. That little rubber line is supposed to pull vacuum at the EGR valve during partial throttle, (2K-3K RPM). It's job is to recirculate hot exhaust gases back into the intake manifold reducing the production of NO gases. Don't ask me how I learned all this stuff. I know it's supposed to be good for us, but there are times where I HATE california smog emission laws.....
ID

[A17Z]

thanks guys! Forgot to mention that I only have a Greddy Power Extreme exhaust and ASP pulley. So I'm pretty much stock.