Reasons for Tractor Stall

During the operation of the tractor, sometimes it will self-extinguish. There are many reasons for this failure, and the signs before the tractor is turned off are also different. When the tractor has a self-extinguishment failure, it must not be restarted without identifying the cause, otherwise a greater accident may occur. The main causes of the tractor's self-extinguishment are the following aspects.

 

1. Self-extinguishment caused by severe overload operation

 

When the tractor is in operation, the external load suddenly increases, which greatly exceeds the rated load of the engine, the engine speed will drop significantly, and the air volume in the cylinder will be relatively reduced. However, the over-supplied diesel can not be fully burned and discharged in the form of black smoke, and the tractor automatically shuts down.

 

For example, if the tractor hydraulic device fails, and the farm tool is suddenly too deep into the soil, or when the farm tool encounters obstacles such as tree roots or large dark stones in the field, or it is overloaded seriously during transportation and encounters uphill or muddy, even it is  driving on the road, the tractor will self-extinguish.

 

2. Self-extinguishing caused by low-pressure fuel circuit failure of fuel system

 

No fuel is supplied to the fuel system, and the engine must be turned off.

When the speed of the engine is unstable and the flame is gradually turned off, the possible reason is in the low-pressure oil circuit.

 

First, the fuel in the fuel tank is exhausted and the oil is not supplied; Second, there is air and water in the oil road. There is a damaged place or a clogged oil passage to supply oil; The third is that the oil pump is damaged and cannot be supplied with oil.

 

At this time, check the fuel in the fuel tank. Check whether the vent hole of the fuel tank cap is blocked, and also check whether there is air or moisture in the fuel system, and whether there is any damage or leakage in the fuel pipe and each joint.

 

Set the throttle to the neutral position and crank the crankshaft. If the sound of fuel injection is not heard, the air is entering the low-pressure system of the fuel system. Check whether the fuel pipe and all joints are damaged or leaking, and drain the air before starting.

 

If the speed is not stable after an increase in load after starting, the oil circuit may be blocked or the diesel is dirty. In winter, the oil path is blocked by water freezing in the oil.

 

3. Self-extinguishment caused by malfunction of gas distribution mechanism

 

Put the throttle in the neutral position and crank the crankshaft. If you can hear the sound of fuel injection, it may be a malfunction of the gas distribution mechanism. The leaking compression of the cylinder is weak, and the high temperature and high pressure conditions required for diesel combustion cannot be formed, causing the engine to be interrupted and automatically shut down.

 

The main reason for this failure of the gas distribution mechanism is as follows.

 

(1) The valve is stuck in the catheter;

 

(2) The valve spring is broken, so that the valve cannot be closed or not closed tightly;

 

(3) Loose adjustment screw makes the valve clearance too large. In severe cases, the push rod is disconnected from the rocker arm, and the valve cannot be pushed to work;

 

(4) The decompression mechanism is damaged, so that the tractor engine cylinder is not compressed;

 

(5) The valve spring falls off, causing the valve to fall into the cylinder and get stuck on the top of the piston;

 

(6) The air distribution camshaft and the sleeve (mainly the front sleeve) bite tightly;

 

(7) The air distribution camshaft and the air distribution timing gear fall off.

 

The gas distribution mechanism fails, and abnormal sounds or abnormal smoke of the exhaust pipe occur before the tractor engine suddenly stops. At this time, the engine should be stopped and repaired immediately, and then restarted after finishing. Special attention should be paid to prevent the valve from falling into the cylinder, otherwise it will cause a major accident of breaking the tractor cylinder head or cylinder body.

 

4. Self-extinguishment caused by severe air filter blockage

 

If the exhaust pipe emits black smoke at the same time when you feel that the power of the tractor diesel engine is obviously insufficient, it may be that the air filter is seriously blocked, causing the cylinder to shut down without air supply.

 

5. Self-extinguishment caused by damaged cylinder head gasket

 

Before the tractor self-extinguishes, if the exhaust pipe emits white smoke, there is water in the diesel and the cylinder gasket is ablated. The function of the cylinder gasket is to seal the combustion chamber and prevent water leakage, air leakage and oil leakage. However, the ablation of the cylinder gasket will affect the sealing performance of the cylinder, resulting in weak compression of the cylinder, causing the engine to self-extinguish.

 

To further determine whether cooling water has entered the combustion chamber, check whether there is water in the engine oil, and replace the tractor cylinder gasket and tractor engine oil if necessary.

 

6. Self-extinguishment caused by high-pressure fuel circuit failure of fuel system

 

If the above-mentioned abnormal phenomenon does not occur before the diesel engine is turned off, it is generally due to a failure of the high-pressure oil circuit, which suddenly stops the fuel supply and causes an automatic flameout.

 

For example, failures like the needle valve and the needle valve body are stuck, the fuel injector cannot be injected, the single-cylinder plunger or the outlet valve spring is broken and the oil supply is not supplied, will cause tractor automatic shut down.

 

7. Self-extinguishing caused by failure of crank connecting rod mechanism

 

When the main moving parts of the engine such as tractor crankshaft and bearing pad, piston and tractor cylinder liner are stuck with each other, the tractor diesel engine will be forced to automatically shut down. Check whether the crank connecting rod mechanism of the engine is stuck. Shake the crank, if it cannot shake, it can basically be determined to belong to this type of fault.