The carburetor is a crucial part of many engines and—although it has been replaced by fuel injection in recent models—it was a key component of older vehicles. It is the part of the engine that controls the air to fuel mixture that permits efficient combustion. If you are an enthusiastic vintage car tinkerer or auto show participant, you will undoubtedly come across a carburetor that needs to be repaired. Here are a few troubleshooting tips.

3 Tips for Troubleshooting Carburetor Problems

1. Car Won't Start

If you have trouble getting the engine to catch after turning over several times, it could indicate carburetor problems. Fortunately, the solution is often a simple one, and you can be off to the auto show in no time. Try adjusting the main mixture screw. Check maintenance literature for your vehicle for the proper adjustment. Some models require the main screw be finger tight, while others suggest you adjust it one to one and a half times counterclockwise for the best results. If this is not the problem, adjust the idle mixture screw similarly.

2. Car Won't Idle or Idles Too Quickly

If the car starts but the engine dies after a few seconds, it’s probably due to an improperly adjusted idle mixture. The same is true if the engine is idling too quickly. To solve the problem, first, make small adjustments to the idle mixture screw in one direction. If idling becomes rougher and less even, adjust the screw slowly in the other direction. Continue doing this until you achieve a smooth, steady idle.

3. Carburetor Leaks

Fluid leaks—and fuel leaks in particular—are a common auto show embarrassment and should be addressed before you attend. Even though it's not large, a carburetor can leak fuel from a number of spots, creating combustion danger and wasting fuel. Inspect the idle and main mixture adjustment screws and O-rings for cracks and damage. If these are in good shape, check the caps, plugs, and gaskets for moisture. Repairs of this type can become complex, so it's often best to have a professional handle it for you.

To show off your project car or view thousands of restored classics, visit the Charlotte AutoFair, a longstanding, biannual vintage auto show in Mecklenburg County, NC. It's been a favorite destination each spring and fall for car fanatics for more than 30 years. Visit their website to learn about attendance information, or call (704) 841-1990 to speak with a friendly representative.