What Causes the Rich Mixture in Cylinder 1 of a Mercedes-Benz?
2 Answers
For the phenomenon of a rich mixture, the following reasons are generally involved: 1. Possible poor performance of related sensors: such as the oxygen sensor, coolant temperature sensor, intake air temperature sensor, throttle position sensor, air flow meter, or intake manifold pressure sensor. 2. Severe clogging of the air filter: If the air filter is severely clogged, or if there is a dripping phenomenon in the fuel injector, or if the fuel pressure regulator is performing poorly, it can also lead to a rich mixture. 3. Throttle and fuel injector: Clean the throttle and fuel injector, replace the spark plugs, and if that doesn't work, the oxygen sensor may need to be replaced.
I've worked on quite a few Mercedes-Benz vehicles, and the issue of cylinder 1 running too rich is quite common. The most frequent cause is a problem with the fuel injector, such as the injector for cylinder 1 being stuck or leaking, causing too much fuel to be sprayed and lowering the air ratio. It could also be that the mass airflow sensor is dirty or faulty, sending incorrect signals to the computer and causing it to inject more fuel. Another possibility is a vacuum leak in the cylinder area, which prevents enough air from entering, resulting in a rich mixture. Additionally, an oxygen sensor providing incorrect feedback can cause the engine control module to supply more fuel. If you notice a sudden increase in fuel consumption, black smoke from the exhaust, or poor acceleration while driving, it's important to pay attention. Leaving this issue unresolved can lead to carbon buildup in the engine, fouled spark plugs, and even damage to the catalytic converter. It's recommended to start by using an OBD scanner to read the fault codes for initial diagnosis, but it's best to take the car to a professional repair shop for a thorough inspection of the injectors and related wiring. Mercedes-Benz's electronic systems are quite complex, and DIY repairs can easily go wrong—safety first, don't delay.
