The C5 engine emits black smoke from the exhaust pipe at high speeds, and the smoke is noticeable wh

I have encountered similar failures for reference!

Fault diagnosis and elimination: According to the above fault phenomenon, the analysis believes that the black smoke fault of the engine exhaust pipe is usually caused by the excessive concentration of the mixture, and the main reasons are: the failure of the absolute pressure sensor of the intake manifold, the failure of the coolant temperature sensor and the oxygen sensor.

Detected with a decoder, without any fault codes. Looking at the data stream, it is found that the signal value of the oxygen sensor is out of the range, which is 0 and normal. At the same time, it was found that the injection pulse width of the injector gradually increased from the engine when the engine was just started, and continued to rise, and the black smoke emitted from the exhaust pipe became more and more dense, which was preliminarily diagnosed as the vector effect of the oxygen sensor.

Dismantling and testing of the oxygen sensor found that the side air hole was blocked by carbon deposits.

Therefore, after replacing the oxygen sensor, start the engine and check the data flow, the signal value of the oxygen sensor and the fuel injection pulse width of the fuel injector are within the normal range, and the black smoke from the exhaust pipe disappears.

But the next day, the above failures were repeated. Connect the decoder to view the data stream. Start the engine, let it idle and read the signal value of the oxygen sensor and the pulse width of the fuel injection, which are within the normal range

When I continued to observe for about 10 minutes, it was found that the signal value of the oxygen sensor and the fuel injection pulse width of the fuel injector were gradually inaccurate, and black smoke gradually came out of the exhaust pipe. After analysis, it is believed that the cause of the fault is that the mixture is too concentrated to affect the working performance of the oxygen sensor until it fails, and the signal value of the oxygen sensor is inaccurate, resulting in an increase in the injection pulse width of the injector.

The intake manifold absolute pressure sensor, coolant temperature sensor, and throttle position sensor and their wiring were inspected, and no abnormalities were found. Therefore, it is determined that the cause of the fault is the inaccuracy of the signal value of the oxygen sensor. There are several reasons for this:

There is a problem with the gasoline crystal, or the oxygen sensor wiring and the engine ECU itself are faulty.

So check the oxygen sensor circuit. Remove the engine ECU, measure the continuity of the oxygen sensor terminal to the ECU wire side connector terminal again, and shake the wire while measuring, the conductivity is poor, and it is suspected that the ECU connector is in poor contact. Then install the ECU connector and oxygen sensor, connect the decoder, start the engine, read the data stream, and the signal value of the oxygen sensor quickly drops to zero.

Insert a pin from the rear of the ECU harness connector terminal, and the signal value of the oxygen sensor immediately returns to normal. This indicates that the engine ECU connector is in poor contact.

Hope it helps!

First check the oxygen sensor, water temperature sensor, analyze the injection pulse width, check the fuel injector, and check the carbon canister. The main thing here is that the canister inspection should not be ignored and <>

You can take a look at the maintenance cases you have encountered, and I hope it can help you.

When black smoke is emitted, it is often accompanied by a decrease in engine power, too high exhaust air temperature, and too high water temperature, which leads to wear of engine parts and reduces engine life. The causes of this phenomenon (there are many causes of incomplete combustion) and how to eliminate them are as follows.

1) The exhaust back pressure is too high or the exhaust pipe is blocked. This situation will cause insufficient air intake, which will affect the air-fuel mixing ratio, resulting in excessive oil volume. This is the case:

First, there are too many exhaust pipe bends (especially 90° bends), which should be minimized; The second is that the inside of the muffler is blocked by too much soot and should be removed.

2) Insufficient air intake or blocked air intake duct. In order to find out the cause, the following checks should be carried out: first, whether the air filter is blocked; the second is whether the intake pipe is leaking (if this phenomenon occurs, the engine will be accompanied by a harsh whistling sound due to the increase in load); The third is whether the turbocharger is damaged.

The blades of the exhaust gas wheel and booster wheel should be checked for damage and whether the rotation is smooth and flexible; Fourth, whether the intercooler is blocked.

3) Incorrect adjustment of the valve clearance, poor contact of the valve seal line. Valve clearance, valve springs and valve seals should be checked.

4) The oil supply of each cylinder of the high-pressure oil pump is uneven or excessive. The uneven oil supply will produce unstable speed and intermittent black smoke, which should be adjusted to make it balanced or within the specified range.

5) If the injection is too late, the advance angle of the injection should be adjusted.

6) If the injector is working poorly or damaged, it should be removed for cleaning and inspection.

7) Injector model selection is incorrect. Imported high-speed engine has strict requirements for the selected injector (injection hole diameter, number of holes, injection angle), if the choice is not appropriate, it will also cause the engine to emit black smoke, even if the same model of engine, in different use occasions (output power, speed, etc.), the injector model required to be used is not the same. If the incorrect injector is selected, the correct type of injector should be replaced.

8) Diesel is of poor quality or the grade is wrong. The imported high-speed diesel engine equipped with a direct injection combustion chamber with a porous injector has strict requirements for the quality and grade of diesel due to the small aperture and high precision of the injector, otherwise it will also cause the engine to emit black smoke and even make the engine unable to run normally. Therefore, clean and qualified light diesel oil should be selected, and it is recommended to use 0 or +10 in summer, -10 or -20 in winter, and -35 in severe cold areas.

9) The wear of cylinder liner and piston assembly is serious. When this happens, the piston ring seal is not tight, and the air pressure in the cylinder drops seriously, resulting in the diesel fuel can not be fully burned and black smoke is emitted, and the engine power drops sharply. Wear parts should be replaced.

The engine emits black smoke during rapid acceleration, while it is normal under other operating conditions. This is the result of inadequate combustion.

The black smoke emitted from the automobile engine is caused by insufficient combustion of fuel, which is caused by excessive oil intake, insufficient cylinder pressure, and engine aging.

The solution is to replace the fuel injector and cylinder collar with a new one, and this problem can be solved.

"White smoke from the exhaust during cold starting, and white smoke disappearing after the engine warms up should be considered normal, if the vehicle is operating normally with a large amount of white smoke, you need to go to the repair shop to replace the gasket. That may be because the cylinder head is not tightly sealed, and a large amount of engine heat flows out, which makes the exhaust pipe temperature too high, and the water and carbon dioxide in the exhaust do not condense into water droplets and are directly discharged. Secondly, for the exhaust pipe that emits blue smoke, there is basically a situation of burning engine oil, which may be due to the excessive gap between the spark plug and the cylinder, the aging of the oil seal, and so on.

It is recommended to check whether the engine cylinder seal is damaged, and change the oil with higher viscosity, otherwise it will weaken the power, increase fuel consumption and even pull the cylinder for a long time. Finally, it is the most important one to pay attention to, that is, black smoke from the exhaust pipe, like tractor smoke, which is generally due to insufficient combustion of gasoline, resulting in carbon accumulation in the engine. If the engine shakes severely, the exhaust pipe not only emits black smoke but also makes abnormal sounds, and the acceleration is weak.

Then we need to go to the repair shop to check the spark plugs, oxygen sensors and air flow meter lamps to troubleshoot. ”

There are generally two types of car engine starting difficulties:

1. The starting performance of the engine gradually deteriorates, and the starting time is getting longer and longer;

2. The engine has always been very good in starting, and it suddenly deteriorates one day. The engine starts to deteriorate chronically, mostly due to poor battery performance. In this kind of car, when turning the ignition switch to start the engine, the speed of the engine is instantly high, and then the starter appears to be underpowered, so that the engine speed is extremely low, and it takes a long time to start the engine.

In this case, the old battery must be removed as soon as possible and replaced with a new one. After the battery is replaced, the starting performance of the engine can be improved immediately after the battery is replaced. If the engine has been poor in starting for a long time, it is likely that there is a problem with the ignition system or fuel supply system.

For example, the spark plugs, high-voltage wires, ignition coils, etc. in the ignition system are faulty, and the carburetor in the fuel supply system is poorly adjusted. To solve this kind of problem, you need to have some skills, and it is best to ask a professional repairer to help check it before the problem worsens. If you don't have the skills to do it yourself, it's best not to make adjustments.

In the case of white smoke, there should be a lot of burning water. It is advisable to see if it is a problem with the engine itself.

Acceleration is black smoke is good for not burning. It mainly includes the imbalance of oil and gas, or poor atomization, poor combustion, etc.

More oil: The oil pump has a larger amount of oil. Less gas:

Damaged supercharger; Air intake line leakage. When the air is thin and not enough at the plateau. There is also a sharp acceleration, the response of the supercharger can not keep up, and the air intake is insufficient and the atomization is not good

The injector was blocked by carbon deposits due to oil quality and other reasons. Or the fuel injector burns and other reasons cause the atomization to deteriorate. Burning:

The advance angle of the injection is too small. The oil pump is broken and the injection pressure is too small.

1. Causes of black smoke.

1.The flammable mixture is too thick. 2.

There is too much oil in the engine fuel. 3.Poor piston ring or crankshaft oil seal sealing.

4.There is moisture in the fuel. 5.

Bad spark plug 6The air filter is too dirty.

2. Fault diagnosis and elimination.

1.For the inspection and diagnosis of excessive concentration of combustible mixtures, the carburetor and air filter should be checked.

2.The blend does not compare with the blend of the oil, or the wrong grade of oil is used. If the oil mixture contains too much oil or the oil quality is poor, the oil of the flammable mixture cannot be completely burned, resulting in black smoke.

The above phenomenon can also occur in two-stroke engines with separate lubrication and oil pump misalignment and excessive oil supply. At this time, the oil pump should be checked and adjusted according to the regulations to ensure that the lubricating oil is supplied proportionally at different throttle openings.

3.Excessive wear or breakage in a four-stroke engine, as well as too much oil in the crankcase, can cause oil to string into the combustion chamber and cause excessive oil in the mixture. If the crankshaft oil seal of a two-stroke engine is broken, it will also cause the oil from the transmission to string into the crankcase and enter the combustion chamber with the mixture.

4.One of the reasons for the mixing of water in the fuel is that the fuel in the fuel tank itself contains water, so the fuel tank should be cleaned and the fuel should be replaced. Another reason is that the cylinder gasket of the water-cooled engine is broken, and cold water enters the cylinder.

If, in the absence of leakage, the water in the tank is consumed too quickly, and the exhaust smoke from the exhaust pipe is slightly white, this is mostly the reason and the head gasket should be replaced.

Black smoke from gasoline engines is rare, black smoke is mainly not completely burned fuel in the combustion chamber, in the case of high temperature and lack of oxygen, diesel can not be completely and fully combusted, so decomposition and aggregation to form soot, it is a small diameter of the aggregate.

Because this aggregate reacts much slower than gasified fuel, due to the high temperature and anoxic environment of the combustion chamber, it cannot be fully burned again and is discharged through the exhaust pipe, so black smoke is presented.

The direct consequence of this phenomenon is that the fuel consumption of diesel engines is very high, the power is reduced, and at the same time, a large amount of carbon deposits exist in the piston and piston ring valves. In severe cases, the piston rings will be jammed, the valve seal is not tight, and the air leakage will be accelerated, and at the same time, it will also accelerate the wear of parts, thereby reducing the service life of the engine, so this aspect should be paid special attention.

Bad burning, check the spark plugs, high voltage wires, thank you, hope it can help you.

First, the fault phenomenon.

1) When driving under heavy load, you feel weak when you press the accelerator to the end.

2) Significant reduction in climbing ability.

3) When accelerating sharply, the speed is not high or the acceleration is obviously insufficient.

Second, the cause of the failure.

1) The oil specification is wrong, and there is water in the oil.

2) The pull rod stroke of the accelerator pedal cannot guarantee the maximum fuel supply.

3) The fuel supply of the fuel injection pump is insufficient or uneven, and the governor is improperly adjusted.

4) Injector leakage, insufficient pressure, poor atomization.

5) Diesel filter or oil circuit blockage.

6) The air filter or exhaust muffler is clogged or not smooth.

7) Insufficient cylinder pressure or engine overheating.

8) Injection time is too late.

3. Fault diagnosis and elimination.

1) After filling the new diesel, the engine has insufficient power and sensitive eyes, indicating that the diesel quality is not high, the oil number is wrong, and the fuel should be replaced in time; If water is found in the oil, the sewage discharge plug at the bottom of the oil tank and the sewage drain plug of the oil-water separator should be loosened, so that the precipitated water can be released.

2) Check the stroke of the accelerator pedal lever. The accelerator pedal is stepped to the end, and then the fuel injection pump oil volume adjustment arm or the fuel supply rack is pulled by hand, if it can also be pushed in the direction of refueling, it means that the accelerator pedal lever can not make the fuel injection pump reach the maximum fuel supply, and the lever should be adjusted to increase the length.

3) Check the governor high-speed women's limit screw and the maximum oil supply limiting screw. When the high-speed limit screw and the maximum amount of tung oil supply screw are screwed in, the engine feels powerful, which means that the original oil supply is insufficient, and the amount of oil supply is adjusted until the exhaust pipe begins to emit black smoke when accelerating sharply.

4) The exhaust pipe discharges gray-white smoke, which is generally too late for fuel injection.

5) When it is just started, white smoke is emitted, and black smoke is discharged after the temperature rises, indicating that the engine cylinder pressure is insufficient.

6) If the exhaust pipe emits black smoke continuously, especially when accelerating sharply, it means that the air filter bridge is blocked.

7) If the above situation is good, the fuel injection pump and fuel injector should be sent for bench commissioning.