How to deal with the common engine faults?

How to deal with the common engine faults? Today for you to sort out some engine start problems and speed can not go up the fault case for reference. Diesel engine is not easy to start, or the speed is not easy to increase after starting. The force generated by the combustion of gas expansion in the engine cylinder, in addition to overcoming the friction resistance of the engine and driving the auxiliary devices (such as water pump, oil injection pump, fan, air compressor, generator, oil pump, etc.), and finally output power through the flywheel. If the engine cylinder heat is small or the thermal efficiency is not high, its friction resistance is too large or the driving auxiliary device consumption power increased, the engine output power will be reduced, the engine is weak.

Effects of a fuel supply system failure

(1) Insufficient oil supply

The fuel system shall be able to properly spray and atomize good fuel into the cylinder. If the fuel system fails and the amount of oil in the spray cylinder is less, the heat generated by combustion is reduced. When the heat is reduced to meet the engine load, the engine is weak.

(2) The influence of oil injection advance Angle

The amount of fuel injected into the cylinder shall be appropriate. If the fuel in the initial pressure increase rate increases, easy to cause the engine work rough. The rough work will consume part of the power, that is, the thermal efficiency utilization is not high, so the effective power of the external output will be reduced. The advance Angle of oil injection is too small, most of the combustion process is moved to the expansion process, so that the pressure increase rate is reduced, the highest pressure drops, the exhaust temperature increases, the heat loss of cooling water is more, and the thermal efficiency is significantly reduced.

(3) Poor spray quality

When the engine works, the quality of the fuel injector spray is poor, so that the fuel surface area injected into the cylinder is small, and the binding rate with oxygen is reduced. Even if the oil quantity in the injection cylinder is not much, but because of the poor atomization quality, the reaction with oxygen combination is less, and the heat emitted is less.

(4) The influence of the ambient temperature

When the ambient temperature is too high, the engine often causes overheating. Under the dual effect of high ambient temperature and engine overheating, the air expands, thus affecting the inflation amount of the engine and reducing the engine power. When the ambient temperature is too low, it will cause the poor evaporation of fuel oil in the cylinder, resulting in incomplete combustion, that is, the heat generated by the working medium in the cylinder is reduced.

(5) The influence of air inflation volume

Fuel oil in the cylinder can burn, mainly in diesel carbon atoms and oxygen atoms chemical reaction (generate carbon dioxide) release heat, as a result of the air filter blockage make air circulation section reduced (equipped with turbocharger engine turbocharger failure when gas intake decreases) or the influence of the engine inflation is insufficient, resulting in the fuel carbon atoms cannot fully react with oxygen atoms, so the release of heat reduction, engine.

(6) The machine parts containing the working medium are poorly sealed

If the cylinder cushion is damaged, the valve is not closed, the gap between the piston and the cylinder wall is too large, it can cause air leakage and poor compression, resulting in the fuel combustion effect in the cylinder is not good, the engine is weak. The influence of the engine resistance

If the engine assembly is too tight, the oil is too thick, it will cause the engine resistance is too large. The power generated by the engine in addition to overcome the friction and auxiliary device resistance, the effective power output is reduced

Diagnosis and exclusion

(1) If the engine exhaust is low and is not easy to start,

The reason is that the fuel system is insufficient, which should be diagnosed and eliminated according to the fault described in the fuel system.

(2) If the engine exhaust pipe has blue and white smoke,

It shows that the engine weakness is caused by the cylinder movement.

(3) If the engine starts up smoothly

But the exhaust pipe smoke, at the same time the engine speed is not easy to improve, the main reason is that the air into the cylinder is too little, should check the inlet part of the air filter (the engine with a turbocharger but also check the supercharger), and be excluded.

(4) Check the engine resistance

Leverage the engine flywheel with the lever bar, if it feel harder than other diesel engines of the same type or more normal use, indicating that the diesel engine resistance is too large. If the newly repaired diesel engine, most of it is due to tight assembly, should be run in or reassembled.

(5) If the engine overheat

Most of them are caused by the late injection time, which is the cause of the engine failure and should be adjusted. The adjustment method is shown in the statement that the engine cannot start.

(6) Check for air leakage

Leverage engine flywheel to check the cylinder piston compression to stop, remove the injector, hang low speed and hold the hand brake, and then use the hose from the nozzle hole to the combustion chamber with compressed air, then another person in the inlet or exhaust port, oil filling, cylinder cushion or radiator water mouth, listen to the leak. If a gas leak is heard somewhere, the cylinder is poorly sealed. For example, in the exhaust pipe or air inlet, it means that the valve is not closed, or the leakage is heard at the water inlet of the radiator, indicating that the cylinder pad is damaged. It should be identified and excluded.