Hydrocarbon (HC) is basically raw fuel. The number one cause of high HC is
defective ignition system. We'd recommend starting with having a smog check repair station inspect your Ford Thunderbird's ignition system. During the combustion process any number of engine conditions can cause emissions
failures. Out of the three systems your engine relies on to produce
combustion (air intake, fuel delivery, and spark control), the spark system
has the components which require replacement most often. Sparkplugs and
spark wires are constantly exposed to high temperatures and high voltages.
You must ensure your engine's ignition system is functioning properly, by
inspecting all the sparkplugs and their wires. If any of the plugs look worn
out or have excessive carbon build-up replace them immediately. The
distributor cap should also be inspected for cracks or excessive carbon
deposits. If it appears that the cap may be faulty, you will need to replace
it. More then likely you will see an instant performance increase once these
corrections are made. Once you ensure the ignition system is ok, you'll want to move on to the fuel delivery system. A smog check repair station will first have to find out if your vehicle's fuel feedback system is working properly. This includes ensuring the oxygen sensor is working properly, your Ford's
emissions computer is receiving the signals from the oxygen sensor, the
computer is computing the data properly and sending the correct signals to
the fuel injectors to either increase or decrease fuel delivery to the
combustion chambers. Too much fuel in the chambers will cause a "rich misfire", producing high HC. Not enough fuel in the combustion chambers will cause a "lean misfire".
posted by SmogTips Support
