Faults in the diesel engine fuel system: an overview of possible causes and solutions to problems

In the device of any car, whether it's diesel or gasoline, provides a power system (in other words, fuel). There is an opinion that diesel cars are more fastidious to the quality of fuel. This is really so. Yes, and the repair of such a system is at times more expensive. Today we will examine what the diesel engine's fuel system is, its device and the main malfunctions.

Device

Conditionally this system can be divided into two circuits: high and low pressure. The latter produces fuel and directs it to the "next level", to the second circuit. The high-pressure system performs the function of final fuel injection into the combustion chamber of the engine.

The chain of the low pressure circuit includes a number of structural components. This filter, separator, fuel drive, heater, as well as a pump. Fuel passes through each of the above items. The pump creates pressure in the system, the heater warms up the solar oil to the desired temperature in the cold time (because in winter it turns into a paraffinic slurry), and through the filter the fuel enters the second circuit, no less important in the system. It consists of the following parts:

• High pressure fuel pump. It is connected together with the filter.
• Nozzles. Recently, the nozzles with direct injection of fuel have become very popular. It is believed that they are designed for a more accurate dosage of fuel. The machine does not lose power, while the consumption drops.
• Fuel lines are the main lines through which the mixture enters the cylinders.

Below we will consider the main malfunctions of the diesel engine fuel system.

Difficult start up

Especially often this happens in cold weather. It is believed that it is almost impossible to start a diesel without preheating in winter. To somehow smooth out this situation, manufacturers have provided for arctic fuel, which includes anti-freezing additives. But a difficult start does not always indicate a frozen fuel. If the machine is badly started even "on hot", most likely, the high-pressure pump, namely its injection elements, has failed. It is also worth checking the advance angle of the fuel supply to the engine. It is possible to wear the injectors, because of which the mixture is poorly sprayed into the cylinder. In general, there are a lot of reasons for the difficult start of the diesel engine. Therefore, every detail is checked. Faulty glow plugs, improper operation of the pressure regulator, fuel shortage before the injection pump can be defective. Such malfunctions of the fuel system of the diesel engine (Volkswagen T4 is not an exception) are accompanied by depressurization of fuel lines, which causes air to enter the pump, which is no longer able to generate the required pressure.

Power drop

It is due to wear or damage to the spray guns. Also such malfunctions of the diesel engine fuel system occur due to insufficient fuel that gets into the pump. Since a filter is installed before it, there is a high probability that it is simply clogged.

High consumption

The faults in the power supply systems of diesel engines are due to an improperly set injection angle. Also, increased fuel consumption is the result of improper operation of the fuel pump. The injection pressure level of the mixture is too high. In addition, the consumption is increased due to low compression in the cylinders.

Black smoke from the exhaust pipe

And if it is considered to be a "factory disease" at KamAZ, which the owners simply do not pay attention to, then the smoke from the pipe on foreign cars is an occasion to think seriously. These signs of malfunction of the diesel engine indicate a poor mixture formation in the cylinders, which may be due to late fuel injection. Another thing to check is the injectors and the gaps in the valves. The very "blackness" is formed due to the carbon deposits and loose closing of the engine's intake / exhaust valves.

White and gray smoke

Probably, in the engine the head gasket of the block is punched. If this smoke disappears with time, the engine is simply supercooled. This is normal for northern latitudes.

Hard work

The diesel engine by its nature initially operates noisier than gasoline. However, if the vibrations increased, most likely, an early fuel injection occurred. Determining the malfunction of the diesel engine is done by diagnosing the injectors. Also, the level of compression in the cylinders is checked. Its minimum level should be 23 kilograms per centimeter cubic. The run-up of the indicators between the cylinders does not exceed 5-10 percent. The average diesel engine produces about 27-30 kilograms. To determine the use of a special tool - compressometer.

Failures in overclocking

Symptoms: The pedal is too short. In this case, adjust the thrust of the accelerator. Also check the air filter. Perhaps the fuel pump of high pressure is faulty, because of what it can not develop the necessary pressure in the system.

Swim "idle"

In this case, check the sealing washers under the injectors. Look at the mounting of the fuel wire between the filter and the pump. If necessary, tighten more. Also, in case of similar symptoms, the malfunction of the diesel engine fuel system is seen by the pump support plate for damage. It is possible to wear the crankshaft speed regulator . "Idle" swim because of excess pressure of gases in the crankcase - check the ventilation.

The engine has decayed

If it stalls on the move, check the offset of the injection timing. This is a violation of the drive connection to the pump. It is also a dirty filter, due to which there is a shortage of fuel and low supply pressure. As for the pump itself, the piston-separator or rotor can be skewed. It is worth noting that the injection pump is the most expensive part in the diesel engine power system. Due to the complicated design, the element is difficult to repair, so the cost of restoration is comparable to the price of the new item purchased at the disassembly.

Prevention

To exclude malfunctions of the fuel system of the diesel engine (because the diesel breakdown is expensive and for a long time), do not be lazy to carry out preventive maintenance. First of all, it is necessary to flush the system at intervals of 1-2 times a year. This operation involves dismantling the fuel tank and removing the accumulated "sludge" in the fuel filter. Practice shows that at the bottom in the process of operation, a lot of sediment is formed, which, when driven on an empty tank, immediately clogs in filters and lines.

Fuel grade

Especially it concerns the use of the car in the so-called transitional season. The air temperature has already decreased, and at the gas stations they sell the remains of summer fuel. It loses its fluidity already at -5 degrees. Then it turns into paraffin, which is clogged in the pump and filters. Be sure to specify at refueling, what type of fuel will be poured - summer or winter. If it so happened that the temperature dropped sharply, and in the tank the summer "diesel", maximally warm the car with the preheater, or if it's a car, connect the household heater to the garage. When starting a diesel engine every degree is important.

Do not dilute fuel

Some craftsmen, if necessary, run a diesel engine in the winter "bodjazhat" fuel gasoline. This can not be done categorically. In Russia, for a long time, special arctic additives for diesel have been sold, which prevent the formation of paraffin in the tank. In fact, these same additives are added to the usual summer fuel at the gas station - so it becomes suitable for winter operation. There is nothing illegal in this. But dilute it with gasoline - just suicide (meaning for the fuel system).

Warming in winter

Warm up or not? Fuel system of the diesel engine, the device of which differs significantly from the petrol one, also needs this action. After starting the engine, let it run for 3-5 minutes, then the first 200 meters pass in the "gentle" for the car mode. The diesel engine, unlike gasoline, is colder - it takes much longer to warm up. Long work at idle speed is also not required, but ignore the above recommendation is not worth it.

Gas station

Everyone scolds our gas stations for poor fuel quality, they say, there is no normal diesel fuel at Russian gas stations. This is fundamentally wrong. One simple rule: refuel the car with expensive fuel at well-known gas stations. Everyone wants to save by buying fuel at 10-15 percent cheaper than the market value, literally lining up in line. However, after a couple of weeks, after getting on fuel repair, they begin to blame not themselves, but refueling. In fact, this is true, but no one forces to go there by force. You always have a choice. Remember the main thing - miser pays twice.

How to increase the life of injection pump?

As we said earlier, this is one of the most critical parts of the fuel system.

In order for the high-pressure pump to last longer and the diesel engine fuel system malfunction, you should:

• Do not leave the tank at night "half empty". So on its machines condensation is formed, which then penetrates into the nozzles and pump.
• Periodically discharge the sludge through a drain plug.
• Do not ride on an empty tank and a constantly burning light bulb.

Conclusion

So, we found out the main diesel malfunctions. By observing these simple rules, you will significantly extend the system resource and reduce the risk of "getting on repairs".