During the operation of the Carter D10R bulldozer, a large amount of white smoke was suddenly seen from the front of the engine. The engine is accompanied by a heavy peculiar smell and automatically turns off. , The vehicle can no longer start at this time. The maintenance technician found that the drain pipe at the bottom of the water tank was broken and the engine sprayed a lot of mist, mistakenly thinking it was a fire and smoke. Further troubleshoot the following 3 aspects

　　1: Routine inspection. Check the antifreeze of the water tank due to fog, and the liquid level is almost invisible. The water pipe in the lower part of the water tank burst, and there is no antifreeze in the water tank, which caused the engine temperature to be too high, and the engine oil produced peculiar smell. No liquid level rise is found in the engine oil, indicating that there is no leakage of engine oil. Replace the drum-shaped water pipe and add antifreeze.

　　2: Test pressure. Start the engine, the injection brake pressure of the variable oil pump is 40 kg, indicating that the variable pump is normal, but the pressure never rises. After removing the injector, it is found that the oil seal ring is aging and there is a large amount of diesel backlog in the cylinder head. Replace the seals and use The cranking state sprays diesel oil into the cylinder head. The test run still does not start.

　　3: Data analysis. It is suspected that there is a fault in the ECM. Some sensor faults are not recorded by the ECM. The engine still cannot start after replacing the ECM. After cleaning the timing sensor and replacing the injection pressure sensor, it can be started for a short time, but it will automatically turn off. Finally, replace the new timing sensor. Can start normally.

　　Caterpillar D10R bulldozer under high temperature conditions, the seals in the fuel injection nozzle are aging and lose the sealing effect. The timing sensor is a sensor that drives an electromagnet with a voltage of 12.5 V to mark the position of the camshaft. The energized coil has a smaller force under high temperature conditions, but it can still operate, so the engine can be started in a short time. The electromagnet is especially useful in high temperature environments. When used for marking, within the data range, ECM does not record fault alarms. Generally, it defaults to good, only cleaning without considering the change of magnetic force. After replacing the timing sensor, the engine starts normally.