The speed drop of Volvo excavator refers to the speed drop or sudden engine speed drop during the operation after the excavator is started. If the speed drop exceeds 300 rpm, it will be a serious speed drop, which may lead to the car holding fault. Do you know the reasons for the speed drop of the excavator? Let's analyze this problem for you!
Reasons for speed drop of excavator
1. Some cars use the solenoid valve (fuel cut-off) to control the fuel circuit to cut off fuel, so as to achieve the purpose of flameout.
Similar problems have been encountered. The solenoid valve clearance is too large, just like the half effect of flameout wire drawing. The load leads to insufficient oil supply, so the speed drops. The speed drops lead to insufficient oil supply for the diesel pump. This is a vicious cycle, which eventually leads to flameout.
2. The influence of temperature is relatively small. After all, there is a cooling device. The impact of the environment is mainly the air pressure. For high altitude areas, the air is thin, the oxygen content is low, and the engine combustion is insufficient, which affects the engine performance. However, the air booster also reduces the impact of high altitude.
The main reason that affects the engine speed drop is the change of load. When the hydraulic system fails and the displacement cannot be changed, it is easy to cause speed drop or vehicle suffocation.
3. There are two main reasons for the speed drop. The engine performance is degraded and the main pump has problems. Check the engine and the main pump.
You can take out all the hydraulic filter elements by yourself. If you see a lot of copper powder on the filter element, there is a problem with the main pump and the main pump needs to be overhauled.
You can also enter the monitoring panel to check the engine speed. The minimum throttle idle speed is more than 1000 rpm, the maximum throttle idle speed is more than 1300 rpm, and the maximum throttle idle speed is more than 1900 RPM during operation.
If there is no copper powder and the engine speed is normal, the problem can be basically eliminated by removing the two solenoid valves on the main pump for cleaning.
4. If the engine output power is much lower than the rated power, the judgment on the construction site should start with the simplest method.
First, check whether the fuel filter element is blocked, whether there is air leakage in the fuel circuit, whether the plunger, fuel injection head and oil outlet valve in the fuel pump are seriously worn, whether the air inlet of the air filter element is unobstructed, whether the engine with turbocharger is damaged, whether the engine is fast at high temperature, the oil viscosity is reduced, resulting in loose cylinder wall sealing and lower compression ratio, and whether the cylinder liner components are worn, resulting in serious gas crosstalk in the cylinder, The engine valve is not closed tightly, which are the factors that seriously affect the engine power.
If the engine output power is not enough, the matching between the flow of the hydraulic pump and the output power of the engine should be considered.
