Possible malfunctions of the diesel fuel system. The main malfunctions of diesel engines and the fuel system

A power supply system (in other words, fuel) is provided. There is an opinion that diesel cars are more picky about fuel quality. It really is. Yes, and the repair of such a system is many times more expensive. Today we will consider what the diesel engine fuel system is, its device and the main malfunctions.

Device

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

The low pressure circuit chain includes a number of structural components. These are a filter, a separator, a fuel drive, a heater, and also a pump. Fuel passes through each of the above parts. The pump creates pressure in the system, the heater in cold weather heats the "diesel fuel" to the desired temperature (since in winter it turns into paraffin slurry), and through the filter the fuel enters the second, no less important circuit in the system. It consists of the following parts:

• It connects with the filter.
• Nozzles. Recently, injectors with direct fuel injection have gained great popularity. 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 - lines through which the mixture enters the cylinders.

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

Difficult start

This happens especially often in cold weather. It is believed that it is almost impossible to start a diesel engine without preheating in winter. In order to somehow alleviate this situation, manufacturers have provided arctic fuel, which includes antifreeze additives. But a difficult start does not always indicate frozen fuel. If the car does not start well even “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 that the nozzles are worn out, due to which the mixture is poorly sprayed in the cylinder. In general, there are a lot of reasons for the difficult start of a diesel engine. Therefore, every detail is checked. Faulty may be incorrect operation of the pressure regulator, lack of fuel in front of the injection pump. Such malfunctions of the diesel engine fuel system (Volkswagen T4 is no exception) are accompanied by depressurization of the fuel lines, due to which air enters the pump, which is no longer able to generate the required pressure.

Power drop

Occurs due to wear or damage to the nozzles. Also, such malfunctions of the diesel engine fuel system occur due to insufficient fuel that enters the pump. Since a filter is installed in front of it, it is likely that it is simply clogged.

Big expense

These malfunctions of the power supply systems of diesel engines occur due to an incorrectly set injection advance angle. Also, increased fuel consumption is a consequence of improper operation of the fuel pump. Mixture injection pressure level too high. In addition, consumption increases due to low compression in the cylinders.

Black smoke from the exhaust

And if on KamAZ trucks this is considered to be a “factory disease”, which the owners simply do not pay attention to, then on foreign cars the smoke from the chimney is a reason to think seriously. These signs of a diesel engine malfunction indicate poor cylinder carburetion, which may be due to late fuel injection. You should also check the injectors and valve clearances. The “blackness” itself is formed due to soot and loose closure of the intake / exhaust valves of the engine.

White and gray smoke

The head gasket may have been blown in the engine. If this smoke disappears over time, the motor is simply overcooled. This is normal for northern latitudes.

hard work

A diesel engine is inherently noisier than a gasoline engine. However, if the vibrations have increased, most likely, early fuel injection has occurred. Determining the malfunction of a diesel engine is carried out by diagnosing injectors. The compression level in the cylinders is also checked. Its minimum level should be 23 kilograms per cubic centimeter. The range of indicators between the cylinders does not exceed 5-10 percent. The average diesel engine produces about 27-30 "kilograms". To determine, a special tool is used - a compression gauge.

Gaps in acceleration

Symptoms - too short stroke of the gas pedal. In this case, the accelerator linkage should be adjusted. Also check the air filter. It is possible that the high pressure is faulty, because of which it cannot generate the desired pressure in the system.

Swimming "idle"

In this case, check the sealing washers under the nozzles. Look at the fastening of the fuel wire between the filter and the pump. Tighten more if necessary. Also, with similar symptoms of a malfunction in the diesel engine fuel system, look at the pump base plate for damage. The crankshaft may be worn. "Idle" swim because of the excess pressure of gases in the crankcase - check the ventilation.

Engine stalled

If it stalls on the move, check the offset of the injection advance angle. This is a violation of the connection between the drive and the pump. It is also a dirty filter, which causes a lack of fuel and low supply pressure. As for the pump itself, it is possible to misalign the separator pistons or the rotor. It is worth noting that the injection pump is the most expensive part in the power system of a diesel car. Due to the complex design, the element is difficult to repair, so the cost of restoration is comparable to the price of a new element purchased at a disassembly.

Prevention

To exclude malfunctions of the diesel engine fuel system (because a diesel failure is expensive and long), do not be lazy to carry out preventive maintenance. First of all, you need to flush the system at intervals of 1-2 times a year. This operation includes dismantling the fuel tank and removing the accumulated "sludge" in the fuel filter. Practice shows that a lot of sediment forms at the bottom during operation, which, when driving on an empty tank, instantly clogs up in filters and lines.

Fuel type

This is especially true for the use of the car in the so-called transitional season. The air temperature has already dropped, and gas stations are selling the rest of the summer fuel. It loses its fluidity already at -5 degrees. Then it turns into paraffin, which clogs in the pump and filters. Be sure to specify at gas stations what type of fuel will be poured - summer or winter. If it so happens that the temperature has dropped sharply, and there is summer diesel fuel in the tank, warm the car as much as possible with a preheater, or if it is a passenger car, connect a household heater to the garage. When starting a diesel engine, every degree matters.

Do not dilute fuel

Some craftsmen, if necessary, start a diesel engine in the winter, “bodyate” fuel with gasoline. This is absolutely impossible to do. In Russia, special arctic diesel additives have long been sold to prevent the formation of paraffin in the tank. In fact, the same additives are added to ordinary summer fuel at gas stations - this way it becomes suitable for operation in winter. There is nothing illegal in this. But diluting it with gasoline is just suicide (meaning for the fuel system).

Warming up in winter

Warm up or not? The fuel system of a diesel engine, which is significantly different from a gasoline engine, also needs this action. After starting the engine, let it idle for 3-5 minutes, after which drive the first 200 meters in a “sparing” mode for the car. A diesel engine, unlike a gasoline engine, is colder - it warms up much longer. Long idling is also not required, but you should not ignore the above recommendation.

gas station

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

How to increase the resource of high pressure fuel 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 malfunctions of the diesel engine fuel system bypass you, you need to:

• Do not leave the tank "half empty" overnight. This is how condensate forms on his machines, which then penetrates into the nozzles and the pump.
• Periodically drain the sludge through the drain plug.
• Do not drive on an empty tank and a constantly burning light bulb.

Conclusion

So, we found out the main malfunctions of the diesel engine. By following these simple rules, you will significantly extend the life of the system and reduce the risk of "getting repaired".

Diesel engines of cars are characterized by high reliability, however, the possibility of failure of any components or systems for various reasons during operation cannot be ruled out. You should follow the rules that are regulated by the manufacturer's documentation, otherwise, due to frequent breakdowns and illiterate repairs, the service life of a diesel engine is sharply reduced.

Faults:

• difficult starting of a cold and hot engine;
• idling failures;
• reduction in engine power;
• fuel consumption, as well as oils, have become increased;
• there were noises, knocks in the diesel engine;
• the engine does not hold speed well;
• periodically there is a gray or black exhaust.

Diesel failures can occur for a number of reasons. For example, in the event of improper maintenance and incorrect use. It must be remembered that it is better to carry out diagnostics, repair of diesel engines, as well as adjustment of their components and mechanisms in a proven service center, where experienced craftsmen will provide competent service for your car engine both during the warranty and post-warranty period. They will also provide you with all the necessary information.

It is recommended to change the oil no more than after 7-7.5 thousand km. run. This is primarily due to Russian realities: there are a lot of impurities in domestic diesel fuel, including sulfur, as a result of which the oil tends to oxidize. The quality of the oils used must also meet the standards declared by the manufacturer.

The quality of diesel fuel greatly affects the life of the engine. According to statistics, half of all engine failures in general and the fuel system in particular are directly related to fuel. Imported fuel is more "clean" than Russian, contains less various mechanical impurities and water. However, refueling with foreign fuel will cost significantly more.

All sorts of problems may appear after a poor-quality repair of a diesel power unit, because in order to correctly eliminate all malfunctions, mechanics are required to possess all the design features of the engine. Only high-quality original spare parts should be installed and timely replacement of components should be made. All this will extend the operation of the motor, as well as save finances.

The main symptoms of malfunctions include: difficult starting of the motor. Usually bad compression is the culprit. For the same reason, the engine starts to work intermittently, the fuel is poorly sprayed, and noise occurs.

The natural wear of the engine can be caused by a high mileage of the car, after which defects in the elements of the fuel equipment are noted. The compression is reduced, the piston group is subject to wear. In cold weather, the engine becomes more difficult to start. The signs of natural wear of a diesel engine are indicated by an increase in oil consumption, as well as an increase in crankcase gas pressure.

If the nozzle nozzles are worn out, black smoke appears from the exhaust pipe, and fuel consumption increases. A normal resource for a sprayer is from 60 to 80 thousand km. Long-term operation of the motor with this type of malfunction will eventually lead to burnout of the prechambers.

Quite often, plunger pairs of diesel injection pumps wear out. A sign of their defects is a poor start of a warm engine.

During the operation of engines, the surfaces of mating parts gradually wear out, which changes their original dimensions, and in some cases their shape. This entails a violation of the interaction of parts and the occurrence of certain malfunctions, which may also appear as a result of a violation of the established rules for caring for the engine.

Crane operators and their assistants working on cranes with internal combustion engines must be aware of the signs of certain malfunctions and be able to quickly detect and eliminate them. When troubleshooting, you must use the appropriate tools and fixtures. If it is impossible to eliminate the malfunction on the spot by the service team, immediately notify the administration to send the crane to the workshop or call a qualified mechanic.

Consider the main malfunctions of diesel engines K-559 and K-661 (Table 14).

Table 14

Malfunctions and their causes
2. The electric starter eliminates the lack of	2. Check battery charge
exact speed. Not half-	torus and, if necessary, recharging
battery fully charged
3. Diesel not warmed up enough. Bottom-	3. Warm up the engine, for which
what temperature of oil and water	release from the cooling system
4 Insufficient compression due to: a) high wear or sharp pa-	all water or coolant, warm up, first pouring water at a temperature of 50-60 ° C, followed by pouring coolant heated to a temperature of 70-80 ° C a) replace the piston rings;
elasticity of the piston rings (visible smoke from the breather), b) no clearance in the valves	b) adjust the clearances in the valve
Diesel does not develop	panah full power
1 Feed advance angle has changed	1. Set normal angle
	fuel advance
2. One of several does not work	2 Required-
cylinders (a recycled cylinder is determined by successively turning off the fuel supply to the injectors) due to the fact that: a) the fuel plunger hangs	a) remove the fuel pump, disassemble and achieve free transfer
b) hung or loosely attached to	displacement of plungers in bushings. If this fails, replace the plunger-sleeve pair; b) replace a pair of pressure
seat discharge valve;	valve - seat;
c) the injection spring is broken	c) replace the spring;
th valve; d) hanging of the sprayer needle;	d) remove the atomizer from the nozzle
e) the injector spring is broken;	and try to achieve free movement of the needle in the atomizer body. If this fails, replace the atomizer; e) replace the spring and adjust
e) the passage of gases from the cylinders after	set the nozzle to pressure; f) remove the covers of the brackets
valve leakage	fishing line, inspect the springs and
due to broken valve springs or	valves, replace broken springs. When the valves stick
hanging valves;
g) the uniformity of the feed was disturbed	add a few drops of diesel fuel into the gap between the valve stem and the bushing while turning the diesel crankshaft by hand; g) remove the fuel pump and
fuel plungers	trust him for uniformity
	chi fuel;

Malfunctions and their causes	Remedy
h) air passes into the fuel SI-	h) eliminate looseness of tightening
:theme via looseness joining	which fittings, replace the seals
draining fuel from injectors;	body gaskets;
i) coarse filters are dirty or	i) wash the filters and pipelines
fuel cleaning race iln pipesshro-	water. Check the tightness of
fuel supply water. Fuel suction in the suction line	pipeline connections
3. The turbocharger has deteriorated	3. Remove the turbocharger, find and fix faults
4. Leakage in the supercharged line	4 It is necessary to tighten the corresponding
lucid air: a) in the connection of the discharge manifold with the discharge branch pipe or a break in the connecting durite coupling; b) at the junction of the discharge manifold with the cylinder heads, the gly discharge pipe with hot	existing bolts or nuts, replace gaskets
5. Heavily polluted air cleaner	5. Remove the air cleaner or
tel or snail supercharger	snail and clean
Diesel smokes
1. The lead angle has changed	1. Set normal please
chi fuel	fuel advance
2. Injector malfunctions due to	2. Check and adjust
needle sticking or broken spring	nozzle
3. Diesel after start-up is loaded without	3. Warm up the diesel at idle
preheat
4. Insufficient compression due to	4. Grind valves, replace
looseness of the service valves or high wear or loss of elasticity of the piston rings
Note. A supercharged diesel also smokes at ambient temperatures above +30°C.
Diesel is running amok
In this case, it is necessary to immediately stop the diesel engine with the start handle.
slats; if it is impossible to turn the handle, pull out the tube for supplying top-
liv from the dyuritovy coupling which is	before the coarse filter top-
Liv, and load the diesel as much as possible.	At the same time it is necessary to stop
air flow into the diesel engine by closing the air cleaner with the available hand-
materials (work jacket, tarpaulin, napkin, etc.).
Diesel revs are unstable
1. There is no oil in the crankcase	1. Fill oil into the crankcase
gulyator
2. Faulty fuel regulator	2. Remove the fuel pump from the regulation
	lator, find and fix faults

Malfunctions and and* causes	Troubleshooting Method
Malfunctions related to water and oil systems
1. High water temperature due to:	1. Required:
a) radiator pollution;	a) remove the radiator, clean it from dirt, rinse with a solution that removes scale;
b) pump malfunctions;	b) check the pump, find and eliminate faults;
c) diesel overload;	c) reduce the load;
d) malfunction of the electric fan;	d) inspect the electric fan. Check the fusible links, if they are burned out, replace;
e) insufficient amount of cooling	e) check the presence of cooling
giving liquid	liquid and, if it is not enough, top up
2. Wrong thermometer reading 3. Low oil pressure due to	2. Replace thermometer
	3. Inspect the filter screens and
Soreii filter meshes or loose	Rinse. Turn out the reduction
pressure reducing valve closing	valve assembly with a body made of cor-
ia oil pump	start the oil pump without disturbing the adjustment and tightening the valve spring, flush the valve seat and reinstall
4. Rapid drop in oil pressure	4. Shine atomizer with nozzle
in the system due to fuel ingress	and try to get free
va into the oil due to pinching of the needles	movement of the needle in the housing
pollinators	pollinator. If this fails, replace the atomizer

In this article, we'll take a look at a few common diesel engine problems, and how you can fix them on your own. And we will also figure out why these malfunctions can appear in a diesel engine.

The diesel engine does not pull (does not develop full power), but it does not smoke.

The most common causes of such a malfunction are a decrease in the patency of the coarse fuel filter in the car tank and a decrease in the patency of the fine fuel filter. Many conscientious drivers change the fuel filter after a certain mileage of the car, as prescribed by the car manufacturer. But we forget that any manufacturer of an imported foreign car writes the terms for replacing the filter, counting on the fact that the car will be operated on normal European fuel.

It cannot even occur to them that there may be dirt or water in the fuel, which is a common occurrence in our domestic fuel. Therefore, in order not to harm the engine and not lose power, the fuel filter should be changed twice as often, especially if you visit remote gas stations somewhere in the outback. And best of all, upgrade the fuel system of a diesel foreign car, as described in.

In order to be sure of such a malfunction, you need to change the regular opaque fuel line going from the fuel filter to the injection pump to a transparent hose (as in the photo on the left), which will be very useful in the further operation of the car (after replacing the hose, and the fuel filter, too, you will need bleed the fuel system, that is, remove air, read how to do this).

After replacing the hose (fuel line) with a transparent one, and pumping the fuel system, we start the engine, and if the fuel filter is clogged, then when the engine is running, circulating air bubbles will be visible in the transparent hose, and with an increase in diesel speed, they will be visible even more clearly. Moreover, from the presence of these air bubbles in the fuel system, the diesel engine can work intermittently (“troit”), naturally, engine power is lost from this.

We get rid of such a malfunction by replacing the fine filter, but before that it will be useful to unscrew the drain plug at the bottom of the fuel tank and drain the sediment. It will also be useful to clean the coarse fuel filter (mesh in the form of a barrel) located in the gas tank from dirt.

To do this, many cars have a special hatch (the one in which there is a fitting for connecting the fuel hose), by unscrewing which you can get to the coarse fuel filter. After all these operations, it will be necessary to bleed the fuel system in order to remove air from it (how to do this, follow the link above and read).

At idle and medium speeds, the diesel engine works normally, and at high speeds it works intermittently (“troit”).

Such a nuisance may be due to a malfunction of the gas distribution mechanism of the engine (timing), as well as due to air being sucked into the fuel system, or due to the above-described loss of fuel filter patency (the filter is clogged with dirt).

First, let's make sure whether the fine fuel filter is to blame or not and whether it is worth changing it. To do this, disconnect the fuel hose from the filter fitting (I hope you have already replaced it with a transparent one), which goes to the injection pump. Dip the end of the hose that you removed from the filter fitting into a bottle of clean diesel fuel and now start the engine.

If now the diesel engine works in all modes (at any speed) normally without interruption, then the malfunction was precisely due to a dirty fine filter and it should be replaced. If the malfunction does not disappear, then try to clean the coarse filter located in the fuel tank from dirt (I wrote about this above). Don't forget to bleed the fuel system afterwards.

If after that the malfunction does not disappear, and the fine filter is new, and you cleaned the coarse filter in the tank, then pay attention (when the engine is running) if there are air bubbles in the transparent fuel hose. If yes, then it is possible that the fuel system is leaking somewhere and air is getting into it.

Check all connections of metal and rubber fuel lines and fittings of the tank, pump, return hose (including under the bottom of the car), it may be necessary to tighten the clamp somewhere, or replace the rubber hose cracked from time to time. Typically, leaks are clearly visible in the characteristic wet spots from the fuel. After the leak has been eliminated, the fuel system should be bled (bleeded).

If you have replaced and cleaned all the filters, and no air bubbles are observed in the hose during engine operation (and everything is tight), but still the diesel engine at maximum speed (or above average) works intermittently (“troit”), then it remains to check (which by the way, it can “float away” due to a malfunction of the valve mechanism), and it’s also worth checking and adjusting the thermal clearances in the valves (read how to do this).

But sometimes this does not help, and either valves or restoration of their geometry is required. But before you remove the head for repair, you should determine why the compression is lost - due to leaks in the valve mechanism or due to piston wear.

How to do this, I already wrote and those who wish can read about it. If you are unable to eliminate all of the above malfunctions, then you should contact the services of specialists to repair the engine head and restore the timing to normal operation.

On more modern diesels, in the head of which hydraulic valve compensators are installed, interruptions in the operation of the engine may be due to a malfunction of the hydraulic compensators, for example, if one of them is stuck due to dirty oil. In general, such diesels like better oil and more frequent oil changes (and filters too), just like turbo diesels.

To eliminate the jamming of the hydraulic compensator, in any case, you will have to disassemble the head, followed by washing or replacing parts (if they have scuffs).

When the diesel engine is running, it knocks, and if you sequentially disconnect the fuel lines from the injectors, then the knock disappears.

Such a malfunction may occur due to the failure of some kind of nozzle (for example, the nozzle needle may jam in the open position). You can determine which cylinder injector is out of order by disconnecting the high-pressure fuel lines from the injectors one by one.

Well, the last reason why a diesel engine can smoke and not develop full power is the unsatisfactory operation of the nozzles (for example, wear and loss of tightness of the needle and its seat - I wrote about the diagnosis and repair of nozzles on my own in), but before unscrewing them from the engine and take it to specialists for inspection (pressure testing), first perform the above steps, starting with replacing the air filter.

By the way, I advise you to clarify the mileage of your car, I mean the real mileage (how to find out the real mileage,), since on modern diesel engines with a common rail system, modern electro-hydraulic or piezoelectric nozzles (I wrote about them) walk on our domestic fuel as the rule is no more than 150 - 200 thousand km. And if your odometer does not have low mileage, as described just above, and the car is modern, that is, with a common rail fuel system, then injector diagnostics are definitely needed.

These are far from all possible malfunctions of a fairly run-down diesel engine, and there are other ways to fix them, but I will try to talk about them in one of the following articles (we find the article).

I hope this article will help those drivers who like to fix most diesel engine problems, and the whole car with their own hands, good luck to everyone.

A modern diesel engine, even if not equipped with an electronic fuel management system and a common rail modification, is more powerful, reliable and economical than a gasoline engine of the same size. The condition of the diesel fuel system directly determines these indicators. In the event of a malfunction, one or more of these characteristics are significantly reduced. Reduce time and money spent on repairs by quickly and accurately diagnosing the cause of performance degradation. It is possible to determine which node caused the malfunction of the diesel engine fuel equipment by analyzing its symptoms.

Common symptoms of a diesel fuel system failure

The nature of the operation of the diesel engine immediately before the occurrence of a breakdown indicates how well the flow and combustion of fuel in the cylinders took place. These indications are used in the preliminary diagnosis of the reasons for the decrease in vehicle performance.

Diesel engine does not start well

To start the unit, a long rotation of the starter is required, the start does not occur immediately and at first it works intermittently either.

Faults:

• lack of "diesel" at start-up - the regulator is faulty, or the booster pump;
• lack of fuel in front of the injection pump - air enters the system;
• lack of injection pressure due to wear of high-pressure fuel pump parts;
• advance angle failure;
• poor dispersion of fuel - the nozzle does not provide a sufficiently wide "torch".

In winter, a difficult start-up can be provoked by: failure of one or more glow plugs; the formation of a "paraffin plug" on the injectors when using an inappropriate (summer) type of fuel, the formation of "flakes" in the fuel line due to water (condensate) entering the tank.

Diesel engine does not develop the required power

When accelerating, the engine power is limited at a certain moment, the car does not develop maximum speed.

Faults:

• air ingress in case of damage to the fuel line;
• line clogging;
• malfunction of injectors, wear of their fasteners;
• failure of the high-pressure fuel pump, or its incorrect adjustment;
• incorrect setting of the injection advance angle.

The reason for the lack of fuel can also be a severe clogging of the air filter and an incorrect position of the accelerator pedal due to incorrect adjustment.

The motor is overheating

Temperature indicators are constantly above normal, while the car's cooling system is working.

Faults:

• the adjustment of the injection advance angle has gone astray;
• low fuel dispersion due to nozzle wear;
• detonation due to low-quality fuel.

The phenomenon sometimes occurs when the oil level in the engine crankcase is insufficient, or when it loses its properties from long-term operation.

Engine power has been noticeably reduced

Traction disappears with sharp acceleration, the acceleration time of the car increases. The effect is observed regardless of weather conditions and elevation changes.

Faults:

• insufficient amount of fuel in the system due to a breakdown of the booster pump;
• “poor” mixture - the fine filter is clogged;
• Significant weakening of the injection power - wear of the plunger pair, or incorrect adjustment of the injection pump;
• failure in the settings of the injection control regulator;
• Several injectors or their mountings are worn or damaged.

If problems occur in rainy weather or when driving in the mountains, their source is a lack of oxygen or a short circuit.

Engine runs hard or makes noise

The power unit reacts sharply to the accelerator, there is no smooth acceleration, with an increase in load, a characteristic fractional knock is heard in the area of ​​\u200b\u200bthe cylinders.

Faults:

• displacement of the injection phase towards early advancing;
• discrepancy in the amount of diesel entering different cylinders due to a violation of the adjustment of the nozzles;
• breakage or clogging of one of the sprayers;
• lack of proper sealing at the place of installation of the atomizer (there is no washer, the fastening is too tightened or loosened);
• air enters the fuel line;

In some cases, the reason is the lack of compression of the CPG.

Engine idling unevenly

It is noted mainly after maintenance (repair), or long-term operation without proper maintenance.

Faults:

• incorrect adjustment of the idle speed;
• airing in the section between the filter and the high pressure pump;
• damage to the base plate, in the high pressure fuel pump seal;
• failure of one or more nozzles, or failure of the nozzle or unit injector.

A separate cause of the problem is the limitation of the accelerator pedal travel (dirt, broken traction, etc.).

Significantly increased fuel consumption

It is noted regardless of the vehicle load.

Faults:

• clogging (loss of tightness) of the return channel of the fuel line (on the way to drain excess into the tank);
• idle speed is too high;
• injection advance adjustment failure;
• airing the main line.

Other reasons - clogged air filter; low compression in the cylinders; Timing gear needs to be repaired.

The computer gives an error

A vehicle equipped with an on-board computer displays a check engine message, or "engine error", if the pressure in the low pressure line or the fuel rail (common rail) does not correspond to the working indicator. Depending on the brand of the machine, the error code will be different.

Faults:

• the flow control sensor has failed;
• air entering the fuel line;
• the injection pump valve is not working properly.

For reliable diagnostics, you will need to connect a car dealer scanner to the on-board computer.

The motor suddenly spontaneously stops.

The car stalls while driving or immediately after starting.

Faults:

• damaged fuel line (faulty connection);
• booster pump broke;
• failure of the drive, piston-separator, pistons or high-pressure fuel pump rotor due to significant wear;
• Injection advance adjustment is broken.

Other reasons: the air filter is clogged, the tightness of the supercharger (turbine) is broken.

Unstable engine operation

The so-called "floating speed" is a spontaneous change by the motor of the readings of the crankshaft speed.

Faults:

• failure of the speed controller;
• the tightness of the fuel system is broken;
• lack of lubrication, or excess slip resistance of the parts of the adjustment system.
• significant production of high-pressure fuel pumps, or nozzles;
• unsatisfactory quality of diesel fuel.

The phenomenon sometimes occurs after a breakdown of the crankcase ventilation valve (CVKG) and the formation of their excess pressure.

Changing the color of smoke from the exhaust pipe of a car

from the exhaust pipe indicates hypothermia of the motor, severe wear of the CPG, or earlier than necessary advancing. Simultaneously with an increase in the level of engine oil, it may be a sign of a breakdown of the cylinder head gasket.

Dark (black) smoke is a sign of improper mixture formation (an excess of fuel and incomplete combustion). Causes: wear or clogging of injectors, “late” injection advance, wear of the CPG with loss of compression, incorrect valve adjustment.

Associated malfunctions of the fuel equipment

They appear either individually or in parallel with the main problems.

• On a car, you often have to change the glow plug - the nozzle corresponding to it is faulty.
• The engine oil level is getting higher - there is a leak in the injection pump drive seal.
• After the trip, it is not possible to turn off the diesel engine - the shut-off solenoid in the fuel line is faulty.
• The car has ceased to provide sufficient "engine braking" force - the return channel (reset) does not work, or the "idle" speed is incorrectly set.

The consequences of a violation are often common: the consumption of a "diesel" can increase both from the wear of the high-pressure fuel pump and from a lack of air when the air filter is clogged. It is possible to reliably establish that the breakdown relates specifically to the fuel system only by successive troubleshooting of the components and assemblies indicated by the problem.