HC emissions

Hello!

Just passed my emissions test, but my HC (hydrocarbons???) was right at the allowed amount. What would cause high HC emissions? I am idling way too high (at 1798 and it should be 1000). Would that cause a high HC reading? Have been having carburetor problems (stalling if gas not being pedaled in - having two do the two foot thing). Would that do it?

Thank you for your time and trouble!!!

HC means misfire.

Hi!

You say misfire. Spark plugs misfire, right? HC - hydrocarbons? Can you explain?

Thank you!

Hydrocarbons are a product of unburned fuel. HC is also the basic formula of fuel and they do not burn if the fuel does not mix with oxygen. Under normal operating conditions, hydrocarbons are supposed to mix with oxygen to form water vapor and carbon dioxide. That is why in the emissions, they show you the 02 and the CO readings. If there is an engine misfire, hydrocarbons will be emitted from the combustion chamber. Engines normally produce hydrocarbons naturally, but a certain amount is able to be converted through the catalytic converter. Hydrocarbons can also be caused by carbon build up in the combustion chamber and you can simply do a carbon cleaning. These are just a few things that can cause excessive hydrocarbons. I hope I could help you understand a little. You may need a new oxygen sensor or the carbon cleaning I mentioned. I am not a professional though, so you need to see a mechanic.

Hi!

Thank you for all the info. My car will not idle - stalls if that given gas constantly. Know I need carbuertor work. Do the high HC levels and the problem with the carburetor link together? I am guessing they do.

Thank you much!

Are you sure you have carbureator? I know that mine which is a 95 has a distributor cap and rotor and no carbureator. The distributor cap and rotor provide the spark to the plugs and when that went bad on my car, it would misfire and die.