Common faults and troubleshooting methods of diesel generators

Diesel generators are a common standby power supply in our work and life, mainly used in highway toll stations, highway long tunnels and various enterprises and institutions. Diesel generators can provide us with stable and reliable power supply, so regular maintenance can improve the service life of diesel generators and give full play to the efficiency of diesel generators.

In order to further let everyone learn about diesel generators, the following will explain the troubleshooting and maintenance of common faults of diesel generators, so as to further improve the efficiency of diesel power generation and improve the business skills of equipment maintenance personnel.

1. Poor ignition of the engine or engine stalling at low speeds. Common causes include low fuel pressure, inlet air in the fuel system, and injector failure.

Exclusion Method:

(1) Make sure there is fuel in the tank. Look for leaks or severe bends in the tubing between the fuel tank and the fuel transfer pump. Check the fuel pressure to see if there is air in the fuel system, if the fuel bypass valve is sticky, jammed or damaged. At full load speed, the minimum outlet pressure of the fuel transfer pump must be 415 kPa. The pressure inside the two fuel manifolds must be from 415 to 450 kPa. If the fuel pressure is lower than that, a new filter should be installed. If the fuel pressure is still low, check the fuel transfer pump and the fuel pressure regulator valve at the fuel manifold.

(2) Find out the air leakage in the fuel system and fix it. If there is air in the fuel system, it is usually entered through the suction end of the fuel transfer pump.

(3) When the engine is running at low speed, the temperature of the exhaust manifold can be used as an indication of the condition of the injector, and the low temperature of a certain exhaust manifold is a sign that no fuel is injected into the cylinder, which may be a fault of the injector. An ultra-high temperature at one of the exhaust manifold ports can be a sign that too much fuel is being injected into the cylinder, or it can be caused by a faulty injector.

2. Insufficient engine power. Common causes include poor fuel quality or water in the fuel, low fuel pressure, air intake system leakage, etc.

Exclusion Method:

(1) Drain the fuel from the tank, replace it with a new fuel filter, and fill it with clean fuel.

(2) Make sure there is fuel in the fuel tank, and check whether the oil pipe between the fuel tank and the fuel transfer pump is leaking or bending. Check to see if there is air in the fuel system, if the fuel bypass valve is stuck, and then check the fuel pressure. At full load, the fuel transfer pump must have a minimum outlet pressure of 415 kPa and a pressure of 415 to 450 kPa in both fuel manifolds. If the fuel pressure is lower than the above, the filter should be replaced. If the fuel pressure is still low, the fuel pressure regulator valve on the fuel transfer pump and fuel manifold should be inspected.

(3) Check the pressure in the intake manifold to see if there is any blockage in the air filter.

3. The vibration is too large after the engine is started. Common causes include loose or faulty shock absorbers, loose engine mounts, misalignment or imbalance of the driven equipment, etc.

Exclusion Method:

(1) Check whether the shock absorber is damaged and tighten the bolts. If the bolt holes of the shock absorber are damaged, they should be replaced with new parts.

(2) Check the alignment and balance, and make corrections if necessary.

4. The valve train is noisy. Common causes include valve springs, spring clamps or valve lifters that are damaged or worn, and lack of lubrication.

Exclusion Method:

(1) Replace the new parts where necessary, the damaged lock clamp can cause the valve to sink into the cylinder, which will cause more damage.

(2) Check the lubrication in the valve chamber, when the engine is running at high speed, the oil should flow in a large amount, and at low speed, only a small amount of oil will flow in. The oil passage, especially the passage of the conveyor oil to the cylinder head, must be clean.

5. There is coolant in the lubricating oil. Common causes are damage to the organic oil cooler core, damage to the cylinder head gasket or water seal, cracked cylinder head, etc.

Exclusion Method:

(1) Replace the oil cooler core and oil filter with a new one, and inject clean lubricant.

(2) Check the protruding part of the cylinder liner flange, install a new water seal in the partition, and tighten the bolts for fixing the cylinder head according to the technical specifications. Replace it with a new cylinder head.

6. The generator is overheating. Common causes include long-term engine overload, blocked ventilation ducts, etc.

Exclusion Method:

(1) Caused by long-term overload of the engine, you should pay attention to the instrument on the point plate at any time, such as: power, power factor, and current should not be overloaded.

(2) If the ventilation duct is blocked, the inside of the generator should be blown clean thoroughly.

7. Too much white or blue smoke coming out. Common causes include too much lubricating oil in the engine, worn piston rings, and damaged turbocharger oil seals.

Exclusion Method:

(1) Pull out the oil dipstick, check the oil level, and discharge the excess oil when there is too much oil.

(2) The gap is too large due to excessive wear of the piston ring, and the oil enters the combustion chamber to participate in the combustion, which will cause blue smoke, and it is necessary to replace the piston ring with a new one.

(3) Check whether there is oil in the intake manifold and repair the turbocharger if necessary.Learn more