How to Deal with Excessive Engine Exhaust?
2 Answers
Methods for handling excessive exhaust in diesel engines are as follows: 1. Poor injector performance: If the injector has poor atomization or dripping, it is particularly noticeable at low speeds of the diesel engine. The lower the speed, the more smoke is emitted. Use the single-cylinder fuel cut-off method to check each cylinder one by one. When the fuel supply to a certain cylinder is temporarily stopped, the black smoke phenomenon reduces or disappears. Replace the injector. 2. Incorrect fuel injection timing adjustment: If the fuel injection timing is too late, post-combustion increases, and the fuel cannot be completely burned, forming carbon smoke that is expelled, resulting in black smoke emission. Adjust the fuel injection timing to an appropriate position. 3. Excessive fuel supply from the injection pump: If the fuel supply is excessive, continuous black smoke is emitted, and the larger the throttle, the more black smoke is emitted. Use the fuel cut-off method to check. When the fuel supply to a certain cylinder is stopped, if the smoke disappears, and the injector is working normally, it can be concluded that the fuel supply to that cylinder is excessive. Reduce the fuel supply to that cylinder appropriately or replace the injection pump. 4. Clogged air filter: After the air filter element is clogged, the air intake of the diesel engine decreases. With the same amount of diesel injected into the cylinder, there is not enough air to mix with it, resulting in incomplete combustion of the diesel and black smoke emission. Replace the air filter. 5. Excessive load on the diesel engine: When the vehicle accelerates, climbs, or the diesel engine is overloaded, more diesel is injected into the combustion chamber. However, excessive diesel and uneven air mixing still inevitably lead to localized insufficient air for combustion. The diesel decomposes and polymerizes into carbon smoke under high temperature, high pressure, and oxygen-deficient conditions, expelling black smoke with the exhaust. 6. Poor diesel quality: If the diesel engine uses inferior diesel or diesel containing other impurities, incomplete combustion occurs, resulting in black smoke emission. Replace with high-quality diesel.
Last time my car's exhaust pipe was emitting black smoke with excessive exhaust fumes. When I took it to the repair shop, the mechanic said it might be due to clogged fuel injectors or a faulty catalytic converter. For self-inspection, first check if the check engine light is on. If not, examine the fuel system to see if the fuel injection is normal—clean any clogs if found. Then inspect the ignition system; severely worn spark plugs can cause incomplete combustion. A dirty air intake filter can also obstruct airflow. I was also advised to switch to higher-quality gasoline to reduce carbon buildup and avoid prolonged idling. Regular maintenance is crucial—cleaning the throttle body every 10,000 kilometers makes the entire process much more hassle-free and cost-effective.
