Dongfeng popular commercial vehicle 49 1 engine three-cylinder combustion is not good. Do you know any heroes?

Hello, dear! Engine cylinder missing: generally divided into 1 and misfire. Remove the spark plug, install it on the high-voltage line, start the motor and watch the spark. Normal sparks are white. If there is no spark or the spark is red, check the spark plug, high voltage line and ignition coil. 2, no oil. Remove the nozzle and connect the oil tank below. Start the motor to see the quality of fuel injection. Under normal circumstances, it is intermittent atomization. If there is no oil, the oil is continuous and there is no atomization. Check the fuel nozzle, connecting pipeline and TCU. 3. No pressure. Remove the spark plug and measure the pressure with the cylinder pressure gauge special for the engine. Fully open the throttle and start the motor. Look at the highest value of the watch. Compared with the pressure of adjacent cylinders, the difference is not less than 5%. Can check the cylinder gasket, intake valve, exhaust valve and piston ring. In addition, there is a special case that the near exhaust passage of this cylinder is blocked by foreign objects.