Diesel generator starting after the analysis of a large number of blue smoke exhaust

Diesel generator starting after the exhaust of smoke, and the operation of the engine in the process of hearing a rhythmic, crisp cylinder metal percussion sound

Malfunction analysis:

This kind of trouble is usually caused by the premature injection time. During the operation of diesel engine, the injection time is too early, and the fuel will be injected into the combustion chamber when the temperature and pressure are lower. The diesel ignition time will be prolonged, and more diesel oil will be accumulated in the combustion chamber. As soon as they get angry, the diesel burns at the same time, and the temperature and pressure increase sharply, causing knock. When the injection time is too high, when the piston is still moving up the TDC, the diesel will burn, causing the pressure to increase rapidly, and the cylinder will produce a crisp metal knocking. Discrimination in the operation of diesel generator fuel injection time is early, there are two characteristics: one is the sound of the diesel engine in the rapid acceleration of a sharp, crisp, continuous and similar metal percussion sound; two is in the idle or low load when knocking was accompanied by vibration, high load noise decreases the operation is relatively stable.

Failure cause:

1 diesel engine oil injection pump time is too early.

2, fuel injection pump oil supply interval is uneven.

3 diesel sixteen alkane value is too low.

Troubleshooting method:

1 stop the operation of the diesel engine, remove the high-pressure cylinder in the upper cylinder of the high-pressure pump, then check the fuel supply advance angle of the diesel engine. In the inspection, it was found that when the first fuel injection had just started, the fuel supply advance angle of the diesel engine was about 50 degrees.

Two fixing screws 2 release of high pressure oil pump connected disk drive, diesel engine according to the running direction of the screwdriver pry the flywheel of the diesel engine, diesel engine on the fixed pointer until the alignment of 28 DEG scale gas on the wheel, then the two screws on the drive plate.

3 diesel engine starting to the rated speed, found the cylinder metal percussion sound disappeared, blue smoke phenomenon has disappeared, the fault is eliminated.

9, the diesel engine in the operation process, found in the fourth cylinder near the inlet and exhaust valve, there are a small number of milky white bubbles appear

Malfunction analysis:

This failure is usually caused by the mixing of cooling water and oil in the inner channel when the cylinder head is damaged.

Failure cause:

The 1 cylinder cover in the inlet and exhaust valve at the crack, caused by the cooling water and oil mixture, when the engine rotates, the intake and exhaust valves up and down movement leads into the middle position, the exhaust valve appeared white bubble.

2 the sump is flooded inside.

Troubleshooting method:

1 take out the scale in the oil pan, check the quality and quantity of the oil in the oil pan, and find no cooling water in the oil.

2 wipe the engine oil at the inlet and outlet with cotton yarn, then start the diesel engine up to 800r/min rpm to see if there is any deterioration of the engine oil. It is found that there is still white metamorphic oil from the intake and exhaust doors overflow, stop the cylinder head after the demolition.

After the 3 cylinder cover is removed, press the finger to hold down the water hole of the cylinder head, then pour water into the water channel of the cylinder cover, use the inflator pump of the car to pressurize the cylinder head and the inner pipe of the water outlet, and check whether there is a crack on the cylinder cover.

4 check found that the exhaust door 1cm at one side of the water seeping out, careful inspection found that there are 2cm long tiny cracks, which is the root cause of the failure.

5 replace the new cylinder head, and then assemble, debug and test the engine to return to normal.