What are the causes of an overly rich air-fuel mixture in a car?
2 Answers
The main causes of an overly rich air-fuel mixture in a car include a clogged air filter, a faulty fuel pump, or blockages inside the carburetor. The specific causes and solutions are as follows: Clogged air filter: First, check the opening of the choke valve and adjust the fuel needle. Then remove the air filter screen to see if the engine performance improves. Inspect the pipeline from the fuel tank to the carburetor joint. If there is fuel leakage or blockage, it will cause the mixture to become rich. The solution is to clean or replace the affected parts. Faulty fuel pump: Check the fuel pump, as a malfunction can lead to a rich mixture. The solution is to replace the fuel pump. Blockage inside the carburetor: The main jet or main fuel passage inside the carburetor may be clogged. The solution is to clean and unclog it.
I think the car's air-fuel mixture is too rich, simply put, there's too much fuel and not enough air in the engine. The most common causes are clogged or leaking fuel injectors—excessive fuel injection squeezes out the air; issues with the air system, like a dirty air filter that hasn't been changed for too long, reducing air intake; or faulty sensors, such as a broken oxygen sensor sending wrong signals, causing the ECU to inject more fuel. That time my car had black smoke from the exhaust and skyrocketing fuel consumption. Start troubleshooting with the simple stuff—clean the air filter or fuel injectors, then use an OBD scanner to read the fault codes and confirm the issue. Don't ignore it; high fuel consumption hurts your wallet and causes carbon buildup in the engine. Address it early to avoid major repairs. When driving, pay attention to whether acceleration is smooth, and if you hear unusual noises, check it out immediately. Prevention is always better than cure.
