At present, there are many phenomena of insufficient power and high fuel consumption in the market. Generally speaking, the priority in maintenance is whether there is a problem with the "heart" of the vehicle. The most intuitive performance is the lack of power of the diesel engine, especially in the case of low temperature in winter. As the heart of the whole vehicle, the engine is a complex assembly mechanism. Troubleshooting is relatively complicated, but as long as you master the basic principle of electronically controlled diesel engine, it is not difficult to fundamentally eliminate the cause of insufficient power.

Diesel engine is a mechanical mechanism that converts energy into mechanical energy and outputs it through the full combustion of the mixture of diesel and air in the combustion chamber. Every diesel engine must undergo a strict trial run before leaving the factory, and the inspectors will accurately calibrate the external characteristics of each engine within a certain period of time according to the physical characteristics of the engine itself. There will be some differences between platforms, so the accuracy of diesel engine platform data needs to be considered. Maintain and calibrate the rack according to certain procedures to ensure that the data read by the rack is accurate and the accuracy is within a reasonable range; Putting the same engine on different test benches can verify the differences between the benches.

Strictly speaking, an engine data, the same assembly process and the performance of the same batch of engines should be within a range, thus reflecting the consistency of engines. The engine is a large assembly, and its consistency depends on the consistency of its parts.

Symptoms of insufficient power: reflected in the acceleration performance and climbing ability, especially under heavy load, the diesel engine will obviously lack power, the throttle will be soft, and the speed will not increase quickly; The exhaust is dull, the driving is weak, and the fuel consumption soars ... suddenly, it is mainly judged by the driver's feeling.

The investigation of underpowered diesel engines is mainly divided into three parts: fuel supply system, intake and exhaust system and electrical system.

1, oil supply system:

The composition of the oil supply system: oil tank (fuel pipeline)-coarse filtration-oil transfer pump-fine filtration-high pressure oil pump-* * * rail pipe-injector.

Oil tank (fuel pipeline): the position of oil inlet and oil return pipes, whether the pipe joints are locked, the internal diameter of the pipeline ≥ 12mm, and the length ≤ 10m. Pay attention to whether there are residues and deposits of inferior diesel oil at the bottom of the fuel tank. Maintain a pressure of 0.3 bar under any working conditions, and have suitable openings or safety valves. Whether the fuel pipeline leaks, is blocked or bent, resulting in excessive fuel resistance and insufficient power.

Coarse filtration: It is generally believed that wax deposition of fuel at low temperature will cause the filter element to be blocked and deformed, and the fuel resistance will increase, resulting in insufficient oil supply. In the case of no wax deposition, consider whether the filter element is blocked and deformed due to poor oil products, and there are a lot of residues and other impurities in the filter paper layer. Filter screen size: 3 ~ 5 microns, filtration efficiency 67%. For the coarse filter with hand oil pump, pay attention to whether the hand oil pump button is sucked down.

Oil transfer pump: The oil transfer pump currently used is a mechanical gear structure. As a sub-component of the high-pressure oil pump, because the high-pressure oil pump is currently controlled by BOSCH as an important component of the * * * rail system, this part can try to change the treatment mode together with the high-pressure oil pump.