The carburetor combines fuel and air in the engine by using an intake vacuum supply. The air is pulled down through to the carburetor by the intake vacuum while fuel is siphoned from the carburetor’s fuel bowl. From here, the fuel and air form a combustible mixture that powers the engine. At high engine speeds, fuel is pulled through the metering jets into the narrowest part of the carburetor throat. It then travels down to the intake manifold where it is burned to produce power in the cylinders.
If there is not enough fuel in the mixture, the engine could be damaged or the vehicle will not run at all. This is called running lean. If there is too much fuel, the engine can flood, run poorly, have bad fuel economy, or become very smoky while running. This is called running rich. The carburetor plays an important part in keeping your vehicle in smooth operating condition.
Problems with the carburetor are often attributed to the part becoming dirty. In addition, different parts can fail within the carburetor. For example, if the power valve inside the carburetor becomes bad, a misfire in the engine will occur. This is because the power valve becomes clogged and then a reduced amount of fuel and air is sent to the engine.
Flooding is another problem with the carburetor that can be a dangerous situation. This happens when dirt gets into the needle valve and prevents the valve from closing. Fuel keeps flowing and spills into the carburetor throat. A flooded engine will not start, and is a fire hazard if fuel leaks onto the hot engine.
Since the carburetor can become damaged or clogged over time, you should be aware of the symptoms that indicate the carburetor needs to be replaced.Signs that indicate your carburetor needs to be replaced include:
Poor fuel economy
The vehicle idles too fast
Your car floods when you try to start it
The vehicle has a rough idle
Your car stalls at low speeds
The vehicle hesitates under load
Sometimes, the part can be rebuilt; it just depends on the extent of the damage. Have a professional mechanic make that distinction to get any components of your car repaired as necessary.
This article originally appeared on YourMechanic.com as How Long Does a Carburetor Last? and was authored by Valerie Johnston.