What are the reasons for the lack of power of diesel vehicles

There are many reasons for the lack of power of the diesel engine, involving many institutions and systems. I have sorted out the reasons for the lack of power of the diesel engine for your reference. I hope you can gain something in the reading process!

I. insufficient oil supply

1 phenomenon

When the engine is running without load, if you increase the throttle, the speed can only increase slowly; Under load, the engine is obviously weak and easy to shut down, but the exhaust does not smoke; In case of overload operation, turn off the engine and there is a little black smoke.

2 reasons

1) the control valve in the oil passage of the pump cover is jacked up by dirt or worn, resulting in loose sealing.

2) improper adjustment of fuel injection pump.

3) when the governor works, the speed is too low or fails.

4) the diesel filter is blocked or the oil pipeline leaks.

5) the diesel brand does not meet the requirements.

3. Treatment method:

1) check the control valve and repair or replace it according to the specific situation. And go to a qualified repair shop to adjust the governor.

2) readjust the fuel injection pump.

3) adjust the cable length of the rocker arm for stopping oil supply.

4) clean the diesel filter and seal the oil pipeline.

5) diesel oil of appropriate brand shall be selected according to season and precipitated.

II. Improper adjustment of oil supply advance angle

1 phenomenon

1) when the engine runs at low speed, the engine works rough and there is an obvious cylinder knocking sound; When the accelerator is increased, the speed can be increased rapidly, the knocking sound is more obvious, but it decreases, and the cooling water temperature is high.

2) when the engine is running, the exhaust pipe emits black smoke and the cooling water temperature is high. The engine is overheated and sometimes there is gunfire. When the "throttle" is increased, the speed increases slowly.

2 reasons

Supply oil too early or too late.

3 treatment method

Readjust the oil supply advance angle or replace it, and repair the severely worn adjusting cushion block, roller body, camshaft parts and other parts.

III. insufficient gas supply

1 phenomenon

When the engine is running without load, it emits black smoke seriously, the sound is stuffy, and the power decreases, especially when accelerating. After loosening the connecting pipe between the air filter and the intake pipe, the phenomenon of black smoke is significantly reduced.

2 reasons

1) the air filter is blocked by dirt, the amount of air entering the cylinder is seriously insufficient, and the gas cannot be completely burned.

2) the exhaust pipe is blocked by carbon deposit.

3) the speed of turbocharger decreases.

3. Treatment method:

1) clean the air filter regularly.

2) regularly remove the carbon deposit in the exhaust pipe and eliminate the poor combustion of the engine in time.

3) maintain the supercharger on time and check the turbine and sealing device.

IV. improper adjustment of valve clearance

1 phenomenon

When the engine is running without load, the exhaust pipe emits black smoke intermittently, and there is a slight "clatter" knocking sound on the valve mechanism.

2 reasons

If the valve clearance is adjusted too large, the inlet valve and exhaust valve will open late and close early, and the total opening time of the valve will be shortened. As a result, the exhaust gas will not be exhausted, the air intake will be insufficient, the engine power will be reduced, and the exhaust pipe will emit black smoke.

3 treatment method

Adjust the valve clearance as required, and check and adjust the valve clearance regularly in the future.

V. the machine temperature is too high or too low

1 phenomenon

The engine water temperature is too high or too low, and the power is insufficient.

2 reasons

1) high water temperature is usually caused by long-term overload operation, serious scale of cooling system, excessive oil supply or too late oil supply time.

2) low water temperature occurs shortly after starting in winter.

3 treatment method

1) avoid long-term overload operation of the locomotive, remove the scale of the cooling system, reduce the oil supply and adjust the oil supply time.

2) after starting the vehicle in winter, the vehicle shall not start until the water temperature rises to 40 ℃, and the normal working water temperature shall be maintained at 75 ℃ ~ 90 ℃.

Vi. air leakage caused by wear of relevant parts

1 phenomenon

The air inlet pipe and exhaust pipe have air leakage sound; Bubbles occur around (edge) the cylinder gasket; The gas channeling at the gasoline filler is serious, the exhaust pipe emits blue smoke, and the oil consumption in the oil pan is abnormal.

2 reasons

The valve and valve seat are not closed tightly; The cylinder head screws are not tightened according to the standard torque; Severe oil burn.

3 treatment method

1) clean, scrape and grind the valve and valve seat.

2) if the joint surface of cylinder head and cylinder block is uneven or warped, it shall be scraped or ground to ensure that the installation projection of cylinder liner is within the specified range, and tighten the cylinder head nuts according to the specified sequence and torque.

3) when the parts of cylinder liner and piston bank are not seriously worn, the piston ring can be replaced, and the cylinder liner can be installed by rotating 90 ℃. If the fit clearance exceeds the specified value, the cylinder should be bored and the piston with enlarged size should be replaced.

VII. Loose or stuck moving parts

1 phenomenon

Black smoke when the engine is running; After parking, rotate the engine and feel great resistance.

2 reasons

1) the adjusting arm of the fixed plunger is loose, and the adjusting fork on the fastening oil supply rod is loose

2) the plunger and roller body are stuck, and the spring force of the plunger is too weak or broken.

3 treatment method

1) fasten relevant parts

2) repair worn rolling elements

3) replace the plunger spring with standard size and elastic force.

If it is ordinary mineral oil, replace it every 5000 km or every half a year; Semi synthetic oil shall be replaced every 7500km or every 9 months; All synthetic oil shall be replaced every 10000 km or every year. Change the engine oil, change the engine oil filter at the same time, and check the battery fluid and the fastening of all screws. The above items are common maintenance items. Replace the air filter every 20000 km; Change the coolant every two years. Replace brake oil, power steering oil, transmission oil and gasoline filter every 40000 km or every 3 years. Replace ordinary spark plugs every 40000 km and iridium spark plugs every 80000 km. Replace the timing belt every 60000 km. The following are what you should pay attention to at ordinary times: always keep the inside and outside of the car and the engine compartment clean and tidy; Check the tires frequently to keep the normal tire pressure and the integrity of the tires; Before the motor car every day, pay attention to observe whether there are obstacles around the car and whether there is liquid leakage under the car; When parking at night, pay attention to whether there is slope on the road. In some cases, it is best to engage first gear or reverse gear in addition to manual parking; Develop good driving habits. The car is different from the car. Maintain and protect your car according to the instructions of your car.

Advantages:

  1. Long service life, economical and durable. The speed of diesel engine is low, the relevant parts are not easy to age, the wear of parts is less than that of gasoline engine, and the service life is relatively long. There is no ignition system and less auxiliary appliances, so the failure rate of diesel engine is far lower than that of gasoline engine. Some imported diesel engines can reach 800000-1 million kilometers without overhaul, while gasoline engines are only 400000-500000 kilometers. Low fuel consumption. The fuel consumption of the 2.8-liter electronically controlled common rail turbocharged diesel engine is equivalent to that of the 1.6-liter electronically controlled gasoline engine.

  2. Low speed and high torque. Diesel engines usually can obtain high torque at a very small speed, which is better than gasoline engines on complex roads, slopes and loads. However, the performance of flat acceleration and high-speed driving on the highway is not as good as that of gasoline vehicles.

  3. High security. Compared with gasoline, it is not volatile, has high ignition point, and is not easy to be ignited or explode due to accidental circumstances. Therefore, using diesel is more stable and safe than using gasoline.

  4. More environmentally friendly. The greenhouse effect produced by diesel engine is 45% lower than that of gasoline, and the emissions of carbon monoxide and hydrocarbon are also low. Only in the service life of the whole vehicle, the emissions of nitrogen oxides and PM (particles) are greater than those of gasoline engine. With the continuous progress of technology, its emission has reached Euro III and Euro IV emission standards.

Disadvantages:

  1. High noise and vibration. It affects driving comfort, so passenger cars are relatively less used. However, with the continuous progress of technology, some medium and high-grade diesel vehicles have been quite close to gasoline engines. Major automobile manufacturers at home and abroad have also launched many diesel cars and SUVs.

  2. High manufacturing cost, high requirements for fuel quality and high weight. The fuel injection device of diesel engine is extremely precise and difficult to manufacture. If inferior fuel is used, the service life of the injection device will be seriously shortened. Because the compression ratio of diesel engine is very high and requires high structural strength, the weight and volume will be relatively large.

  3. Because diesel is not easy to volatilize and compression ignition, cold start in winter is not as good as gasoline engine. Even if there is a preheating device, it can only be started after preheating for tens of seconds.

Generally speaking, diesel engine is better than gasoline engine.

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