Inspection Angle (UUs) and Load In Diesel Engine
(Note: This article is general metering and is not tied to any car brand)
It is strange to hear the opinion of a specialist, a diagnostic, the repairman that the injection advance angle in the diesel engine changes only depending on the frequency of rotation of its crankshaft.
Undoubtedly, the speed of rotation of the crankshaft is one of the main parameters (characteristics), accounted for when organizing combustion of the fuel-air mixture in the engine combustion chamber of both diesel and gasoline.
From the rotational speed of the crankshaft - the speed of the movement of the piston in the engine cylinder - the amount of working fluid in the engine combustion chamber and its temperature depends.
With an increase in the rotational speed of the crankshaft, the absolute durations of the flareliest delays (in milliseconds) are reduced, but the relative durations in degrees of the crankshaft turnover increase. It is not necessary to forget about this moment as the injection delay (time between the beginning of the fuel supply by the pump and the injection of fuel into the combustion chamber).
The higher the speed of rotation of the crankshaft, the earlier you need to be injected into the combustion chamber fuel and vice versa.
Is it possible when organizing combustion in the diesel engine cylinders to limit itself to the adjustment of the crankshaft rotation frequency? Or maybe there is something else that requires our attention?
Attention requires the features of mixing and burning in the combustion chamber of the diesel engine.
First of all, diesel refers to engines with internal mixing formation and fuel injection at the end of the compression tact. On the mixture is allocated to only 1 - 3 ms or 12 - 25 ° at the corner of the rotation of the crankshaft of the engine. This is 20 - 30 less than in the engines with external and internal (injection in the intake) mixture formation (most gasoline engines operate on homogeneous - homogeneous fuel-air mixtures).
The diesel engine is capable of working on depleted mixtures with an excess air coefficient at idle and at zero load \u003d 10. The value for dyssets with a superior at full load is within .. \u003d 1.15 - 2.0. That is, the composition of the fuel and air mixture varies from very poor to the poor.
Thanks to the heterogeneous (inhomogeneous) composition of the fuel-air mixture (TVS) in the combustion chamber of the diesel engine, there are areas with a rich and poor mixture, areas where air or only diesel fuel. And, of course, there are so necessary for timely ignition of the field of the fuel-air mixture (TVS) with a stoichiometric composition. That is, a whole set of mixtures.
These conditions are valid for both engines with separate combustion chambers and diesel engines with direct (straight) injection. It is the inhomogeneous composition of the fuel-air mixture (TVS) that allows a diesel engine to work on depleted mixtures.
On the other hand, the same inhomogeneous composition of the mixture (TVS) with smaller values 
is one of
the main disadvantages of diesel engines are the impossibility of complete and smokeless combustion of the fuel and air mixture (TVS).
In addition to visual confirmation written, I want to show you with the diagram of the main processes occurring in the combustion chamber of the diesel engine.
It will not be about the "explosions". We will talk about managed and controlled events that occur in time in parallel and consistently. You need to see this schedule and remember. Temperature changes are especially important.
Figure 1 presents a typical chart of changes in the press engine cylinder and the average temperature T of gases in the function of the angle F, shows the nature of the change in the amount of the amount of the amount of fuel combustion, the rate of its supply, the coefficient of active heat generation X and the heat generation rate
For clarity and simplicity of perception, the diagram is drawn in deployment. We need to consider it from left to right.
The piston moves to the upper dead point, the pressure and temperature of the working body grow, and if there is no fuel injection at point 1, then when the piston moves from the VMT to NMT, the pressure and temperature will decrease (designated by the dotted line).
Fuel supply starts at point 1, at point 2 the first flame languages \u200b\u200bappear.
This periodic delay of ignition and it is characterized by the fact that the piston is approaching the VMT, the volume of the combustion chamber is reduced, the temperature and pressure grow.
Fig. one
The amount of fuel Art during this period is slight, but at high speed
The temperature in the combustion chamber (due to injection) is somewhat reduced, and accordingly the pressure of the compressible air due to the cost of heat to heating and evaporation of fuel.
From point 2 to point 3 - the phase of rapid combustion
It is characterized by the fact that the piston "translates" the VMT, that is, the volume of the combustion chamber is first reduced, and then begins to increase.
Pressure when the piston movement from the NTT reaches the maximum values, the temperature continues to grow. This period characterizes the "rigidity" of the combustion process in the diesel.
During this period, the main amount of fuel Art with the highest speed is injected into the combustion chamber, the heat generation rate increases sharply and reaches maximum values, and then begins to decrease. The coefficient of active heat dissipation X is growing.
From point 3 to point 4 - Slow burning phase
It is characterized by the fact that the piston moves from the NMT to the NMT, the volume of the combustion chamber increases. The pressure p expanding gases decreases, and their temperature T reaches a maximum.
In this phase, fuel injection ends.
At the end of the delayed burning phase, there is some increase in the heat generation rate associated with an additional turbulus of charge at the beginning of the downstream piston. The coefficient of active heat dissipation X is growing.
From point 4 and before the discovery of the exhaust valve - the trigger phase
It is characterized by the fact that the piston moves to the NMT - the volume of the combustion chamber increases, pressure and temperature decrease. The coefficient of active heat dissipation X is stabilized (the coefficient of active heat generation X characterizes the relationship between the combustion processes and the use of the highlighting heat - see special literature).
The burning is a complex physicochemical process that flows in the gas phase. That is, first liquid fuel should turn into steam, and then as a result of chemical reactions, turn into a combustible mixture capable of making mechanical work.
The liquid fuel injected into the combustion chamber is crushed into small drops, it is distributed over it, heats up and evaporates. This is the essence of physical processes, and they proceed with the absorption of heat.
Oxidation processes are multi-stage and are chain. As a result of chemical reactions (proceed with heat release) a number of active intermediate chemical products (peroxides, aldehydes, alcohols, etc.) are formed (peroxide, aldehydes, alcohols, etc.).
Self-ignition is the final result of the development of these reactions.
The true sequence of elementary stages in the oxidation and combustion reactions of motor fuels was not yet fully studied, but the dependence of their velocities on temperature and pressure is characteristic of most chemical reactions.
The above does not mean at all that physical and chemical processes are carried out consistently. Everything happens almost at the same time. The chemical component of the combustion process is somewhat lagged out due to the fact that first, it should appear in the combustion chamber liquid fuel. Smaller drops evaporate the first. As a rule, these small drops are grouped along the edges of the torch of the injected fuel injector. The dynamics of the fuel torch development in the mechanical system is such that it cannot instantly occupy the volume of the combustion chamber in the engine cylinder, first, a slight amount of fuel under high pressure is injected into the cylinder. This is facilitated by the law of supply of fuel (each phase of burning its amount of fuel), expressed constructively in the details of mechanical injection systems. The injection of diesel fuel in these systems is carried out continuously.
In distribution pumps with solenoid valves, the fuel injection is possible. Pump-nozzles of passenger cars provide pre-injection using a hydromechanical drive.
Rechargeable diesel fuel injection systems are advantageous from all previous systems by the fact that, in addition to preliminary and main injections, they also provide additional. In contrast to the two-stage injection used earlier on some brands, under continuous fuel supply in battery systems, the pre-injection is separate.
But now is not about it.
So, a preliminary amount of fuel at high speed is injected into a heated dense gas environment, collapsed and evaporates. Having a small kinetic energy, it is small (1-4 mm 3) the amount of fuel is not able to break through the dense air and remains in the area of \u200b\u200bnozzles and glow plugs. In the process of mixing formation, zones are always formed, where x \u003d 0.85 ... 0.9. These zones serve as centers of ignition of the surrounding more depleted mixture.
By the time of the main fuel injection, the fuel injected into the combustion chamber is predetermined, already ready for ignition and flammifies. In the combustion chamber, pressure and temperature are sharply rising, which contributes to a significant reduction in the delay in the inflammation of the main injection. Diesel fuel under high pressure at the main injection, possessing greater kinetic energy, breaks through the increasingly sealing (already burning) gas medium to all the combustion chamber zones removed from the nozzle.
The movement of the air defined by the design of the intake manifold, the movement of the piston in the compression tact is repeatedly enhanced by moving on the ignition points in different directions by expanding combustion products. Air mass in turbulent motion, pulsating gas streams permeate fuel torches (holes in the sprayer can be from 4 to 10; in most cases - 6h-8.) Under these conditions, the fuel that continues to be injected, burns almost instantly.
The pressure in the cylinder increases in a timely, smoothly and without noise.
The speed of burning liquid fuel is determined
Speeds of its evaporation and mixing the resulting vapors with air
This is true for internal combustion engines operating on lightweight and heavy type of liquid fuel.
Fuel injection into the combustion chamber of the diesel engine is entitled
the drop in temperature (fuel evaporation is accompanied by heat absorption).
The magnitude of the temperature drop depends on the load.
This is especially noticeable in transition modes associated with increasing load.
On page 58 of the first edition of the BOSCH book "Diesel engine control systems" (translation from the German publishing house "driving", 2004 years) shows the characteristic of the start of the injection, depending on the rotation frequency of the crankshaft and the load on the motor of the passenger car during the cold start and operating temperature .
1) Cold Start (<0 °С);
Fig. 2.It is easy to see that at the speed of rotation of the crankshaft 1000 rpm, with partial loads (3) and full load (2), its corresponding load, fuel sows is required. That is, more fuel must be injected into the engine combustion chamber earlier in order for the peak of pressure expanding when combustion gases "hold" for NMT.
The cold launch of the diesel engine is not much different from gasoline. The lack of heat in the combustion chamber and, in connection with this, the bad conditions for evaporation of diesel fuel are compensated by its greater cyclic feed. More fuel (the desired concentration of vapors due to increased fuel supply), its earlier injection (1) and air heating systems - regular functions of all without exception of cold start acceleration systems.
Thus, when fuel injected in compression tact in the combustion chamber, temperature changes are observed.
There is a need to adjust the devices of diesel fuel.
When testing high-pressure fuel pumps on the stand, you must use tables or cards of specified control parameters. These include the conditions under which the TNVD tested must comply with tabular data.
Functions of the TNVD type VE that are subject to attention.
The health of the elements responsible for high pressure;
The health of the elements responsible for pressure in the TNVD;
Health of the elements of ahead of ahead;
Pump performance;
Work frequency controller.
These indicators are considered at specified rotation frequencies and full load.
In 1978, a disconnected adjustment device for the start of supply start-up appeared on the VE type.
Later, correlates of the LFB type appeared (a device for changing the start of the fuel supply, depending on the load). These devices are designed to correct the start of the fuel supply, depending on the load to reduce noise and especially og emission.
What does the word correction mean? Correction - Amendments to the action of measuring instruments, regulators, etc. Depending on the change in the conditions of their operation.
When checking the TNVD, the traffic proofreaders and other reflective devices are checked.
Interesting results can be obtained by comparing the pressure in the TNTD type VE with the proofreader by load and without it on the minimum idle speed. So, with a proofreading pressure on the pump at idle -1.5Ch-2.0 BAR, and without a corrector - 2.5H-3.8 BAR. That is, the piston of the high-pressure fuel pump fuel pump without a corrector is already in the "earlier" position, calculating the increase in the cycle fuel supply.
You know that the pressure in the TNVD type VE affects the change in the UIs in the dynamics. The higher the frequency of rotation of the shaft-the higher the pressure in the fuel pump and the greater the distance moves the hydraulic piston of the ahead of the automatic ahead - before injection.
The main functions of the corrector
Increase pressure in the pump at a start;
Increase pressure in the pump with an increase in the load;
Reducing the pressure in the pump with a reduction in load.
The pressure in the TNVD varies within 1 H-2 BAR.
It allowed:
Provide earlier injection of diesel fuel when starting (thereby improving it);
Reduce pressure on the pump at idle and, as a result, reduce the noise of the diesel engine in this mode;
Variate between the provisions "earlier" or "later" depending on the load. With a decreasing load (from full to partial) and with the constant position of the fuel supply pedal, the start of the feed is shifted to the "later" position. With an increase in the load - to the "earlier" position. And, as a result, the operation of the engine becomes softer, and the toxicity of ogs in partial loads is reduced.
I admit honestly that until the fourth teach of the diagnostacles did not think about the peculiarities of the device for the advanced control coupling of the injection rapid TNVD. It seemed to me a natural understanding that the fuel injection advance angle depends on many factors. Including from the speed of rotation of the crankshaft of the engine and the load. With a more careful consideration of the issue of regulation of UOV, the question surfaced: How exactly is this regulation? Indeed, in the construction of the row TNVD there is only a regulator of the speed of rotation. The device for adjusting the angle of ahead of injection is made beyond the limits of the pump.
So here's about the coupling ... the coupling is like a coupling, nothing special: springs, cargo. Consists of two rolling poles with one center with one center (OM engine 602.911). And it works simply: the higher the speed of rotation of the crankshaft-shaft, the farther from the center of the coupling moves loads and rotate the second half of the coupling (along with the TNVD shaft) in the direction of rotation - before the fuel injection.
I thought about the corrector, but I did not find places that are convenient for its installation in this clutch. A difficult thing is an event in a row TNVD - to organize the adjustment of the loads by load. But with the advent of an inline TNVD with an additional (regulating) sleeve, it became a reality.
"... With the help of electronics, it is possible to introduce an additional (in comparison with standard TNVD) the correction of the operation of the diesel engine. ... "(p.177, the first edition of the Bosch Book" Diesel Engine Management Systems ", translation from the German publishing house" driving ", 2004).
With these examples, I want to say that it is constructively in elements of simple mechanical high-pressure fuel pumps that are responsible for regulating Us in the dynamics, temperature fluctuations in the engine combustion chamber, depending on the amount of fuel injected into it. At one time, such solutions were quite satisfied with car manufacturers and buyers.
Time goes - everything changes.
I believe that we consider all the processes occurring in the engine combustion chamber, depending on the rotational speed, are necessary separately from the processes occurring when the load changes.
To understand the essence of what is happening. It is impossible to divide these processes.
Changing the amount of working fluid entails a change in the rotational speed of the crankshaft. Even in zero load mode.
On page 58 of the first edition of the BOSCH book "Diesel Engine Management Systems", translation from the German publishing house "driving", 2004, it is said: "... The optimal values \u200b\u200bof the injection advance angles are changed depending on the engine load, which requires regulation. The required values \u200b\u200bare set separately for each type of engine and form a field of characteristics that determines the moment of starting the injection depending on the load on the engine, the rotational speed of the crankshaft and the temperature of the coolant ... ".
Thirty-eight years ago it was said about the adjustment of the UI, depending on the rotation frequency of the crankshaft and the load. The possibilities of organizing the optimal combustion of the fuel-air mixture in the engine cylinders at the time were completely different than today.
Vladimir Belonosov
Not a small number of modern cars can ride a diesel engine and therefore many motorists want to know about such a procedure as - to install the fuel injection ahead. The definition and its correct installation has the cornerstone for high-quality diesel engine. It is worth noting the fact that a certain frequency of rotation has its own, universal.
There are already established indicators, for example, for 800 revolutions per minute, and this is idle, the advance angle will be 3 degrees, for 1000 revolutions it increases to 4 degrees, at 1500 it becomes 5 degrees.
Contrary to breaking opinion This dependence is not linear, which can be traced on the example above. To set the most optimal angle for this torque, a mechanism is established, although it is accurate, then this is the simplest piston that is sometimes called the timer. Its movement depends on the flow of fuel, and this in turn turns the wave washer to a certain level.
The general principle of work is very simple, with a more far asleep, the piston raid the waves of the washer on the plunger will be faster, the same, in turn, will begin the flow of fuel to the nozzles.
Essence of UY.
Installing the fuel injection ahead? What gives this procedure and why don't everyone want to adjust this notorious angle? Its optimal definition allows enough, as well as increase the rated power of the car. Most are not suitable so as to minimize the flow of this diesel.Manufacturers of such engines for frequent look at the maximum pressure, as well as on such an indicator as the rate of increase in pressure during fuel combustion. Also, its contributing and the most severe control of the release into the atmosphere of the NOH will also contribute.
In the process of similar nuances The sense of injection advance is gradually lost. I would like to notice the fact that domestic tractors producers excluded the urgent need to install and finishing the injection advance angle. All wines are stringent design features that do not allow making gross errors in the injection setting process. And how can you characterize this advance angle?
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Varieties
In view of all, it was created 2 types of injection advance angles, it is dynamic and static. The static option sets on special marks, as well as in accordance with the instrument indicators.
Second option It has a different principle of operation, it is ahead of either with an increase in the nozzle needle, or on the fact of the beginning of the injection. At the same time, the static version of the angle is approximately equal to the expected point of the fuel fluid supply, as well as the closure of the intake type valve.
All these systems are quite complex for studying and self-replacement or modernization, so that without knowing the case, this area is best not to delve.
Variations and solving problems
Despite all this it is worth understanding that the adjustment of the angles in any engines is performed in a narrow range, which is rigidly tied to the initial, factory values. The most problematic in the installation of the injection definition angle is passenger cars in which it has a chain or belt drive TNVD. With this situation, even the most insignificant error in the calculation and installation of the level simply will not give the engine to start.
The most apparent example is the installation of the fuel injection advance angle in the row TNVD, despite the fact that they are not particularly common. They are almost impossible to adjust the angle of ahead, as it is implemented in distribution engines. But, this problem was solved by Caterpillar, the problem was solved quite easily by means of simple hydrophormulas using spiral slots that are controlled by an electronic system.
As for the popular control of the advance angle by means of the pump section, it was invented and implemented in ZEXEL engines (this is a Japanese company that has previously wore name Diesel Kiki.).
Based on all this, the procedure for setting up and adjusting the angles is best in the car repair shop, since not every person will be able to produce it at home.
As for the installation itself, it is produced in the following next steps:
- The nanos is fixed on the engine itself, but at the same time the mechanism of the drive with gears of distribution is not connected;
- Next, it is necessary to install the moment in the very first engine section, then it is filled with fuel. After that, to rotate the cam shaft, such a procedure will allow to determine the time of the fuel starts, after its determination it is necessary to stop the shaft;
- The next step will be the markup of the pulley of the fan drive, which is located on the engine. This is done when rotating the crankshaft of a diesel engine with the simultaneous installation of the first cylinder at the top of the dead point. After that, there is a mark on ahead at a distance of 2.5-2.7 cm.
Next, it will be necessary to make a combination of 2 labels, the one that is on the block, and the one that is on the pulley. This is done when the crankshaft is rotated and the crushing mechanism
The next step will be the connection of the adjusting washer with its gear. Fastening is made using bolts.
The topic - utopia, the problems of the fuel settings are dedicated to the sections of the profile forums.
Looking for experience, tips, someone else's practice there: Dieselmastera.ru, Dieselirk.ru. Newbies + Theme "beaten", experienced people were tired of poke the nose of each in the right direction, so if your enthusiasm in independent repair and customization will fade, then the topic will soon drown and become trash in the forum archives.
Customize the angle as it is said in the title of the topic you need a micrometer, but this is not all the settings for the corner, it changes from non-working to idle, then to the maximum, and between the case under load (pedalings). I think you understand how much the capacious name is your topic. People with great experiences indulge in stroboscopes ... In general, the topic is the top of the iceberg, or conquer or ask for moderators to remove).
True saying about the exhaust: smelly hard-bitter and at the same time a ringing (hard) sound from Kamaz early ignition,
Smoky sweet, like bakery / fryer and soft / silent engine operation - later. These observations are made on good adjusted nozzles. The lower the opening pressure in the nozzles, the softer engine operation, should be taken into account when setting up for rumor.
At idle the pipe smells unimaginably, it is necessary on the move above 50-60km / h, the rear window and the front of half pulls into the salon.
If the consumption is in your opinion in reasonable limits - twist only the angle of the pump housing measuring the original position, on 2LT it is convenient to measure between the intake and the coordinator housing on the superior 4mm, moving to 1mm (measured by the shanks of the drill) changes 0.06mm angle measured by micrometer , those 3..4 mm there and here in your case. Returning - later, put forward to the inlet - early.
Play with this setting gives only one type of fuel. But you need to set up on the micrometer and fill a new risk. This is the starting point of a long and thorny path called the topic.
Powdish fuel (euro) ringing and the inhemilate, cheap or called cargo "according to GOST" - soft and sluggish.
These observations should be taken into account when setting up on the rumor.
In order for the car to be cheerfully and at the same time, it is necessary to configure the node of the advance piston, the head of the pump at the bottom of it. You will find a way to customize counting half of the victory. According to a respected dieselist, a device for measuring the course of this piston "extremely useful thing". Inspection and ahead of the advance control is connected directly, not counting the load corrector, using the extremely useful thing you need to have a pressure gauge with adaptation.
The motor quickly heats up this early ignition but only if you bind with it. In the summer, too, the KM drove and ready the stove of pies. In winter, very different.
It works on the cold ring - it is from "normal" to "right" and if it works noticeably softer on the progress, and at the same time turns on the warm-up are added very good. The main thing in this node so that the node does not have adjustments to the angle of the advance - insert the scope in the sprocket's axis and relying on the central nut on the extinguishing dating back to the radiator as soon as the shaft starts to turn the hand. Feel free, if there is a move (angle) Before the starts start, leave it alone, if you immediately have an effort to feel the pushes, then you need to upset so that this free move / angle. Detailed turbid and eventually useless for the manual Description of the setup is in the repair book.
Holiday greetings!
Here, the problem was drawn with me related to this topic.
I didn't have enough, mind, and Ave, and I took off my equipment without putting the label, and I did not look at, in general, as it fell.
(Gave it and nozzles to the configuration of dieselists)
Well, accordingly started as it fell, barely or rather.
Now standing under the windows and does not start at all.
You turn around - grasps once and does not develop turns.
Question is minimal: how to set up, have a job get to dieselists (ok 100 km)?
Not very cold
The bush is seen that risks on the pump and the case do not coincide,
But it seems that the TNVD is no longer native.
04.12.2007
That the fuel injection advance for diesel engines is very important, it is not necessary to explain to anyone. Naturally, for each engine speed optimally, there will be some definite angle of ahead, for example, for idling 800 rpm - this is 3 °, 1000 rpm - 4 °, 1500 rpm - 5 °, etc . To achieve such a dependence, which, by the way, is not linear, there is a special mechanism in the TNVD housing. However, it is just a piston (sometimes in the literature it is called a timer), which moves inside the fuel pressure and through a special leash on this or that angle unfolds a special washer with a wave profile. There will be a piston push further - the wave of the washers slightly takes the plunger to the plunger, he will start moving and earlier will begin to serve fuel to the nozzle. In other words, the injection advance angle depends on the fuel pressure inside the TNLD housing and on the degree of wear of the wave profile of the washer. With fuel pressure, as a rule, no problems happens. Well, except that the fuel filter clogs, the plugs of the reducing valve in the open state or weigh the bundle of the supply pump (inside the pump). (Figure 38, Rice39)
fig. 38 Fig.39
Fig. 38. To fully check the reducing valve, it can be turned out from the pump. The plunger inside this reduction valve should not be flared. So it is or not so, you can check by pressing the plunger match. Under the influence of the hand, the plunger should easily move, squeezing the spring.
Fig. 39. . Unscrew the reducing valve on the already removed pump is not difficult. Do the same, without removing the pump, it is already more difficult.
The state of the reduction valve (may be in a stable state) and the supply pump, you can evaluate using the pump of manual fuel swap. If the engine work changes after you when you run the engine running to swing a manual pump, i.e. You will begin manually lift the pressure in the TNVD case, it means that or the valve, or the pump is faulty. The reduction valve is easily turned, without removing the pump, and check. Only at most diesel engines of the company "
Mitsubishi. »To do this, it is necessary to remove the corner of the bracket with a thin chisel, after which the head of the reducing valve becomes available for a special key. By the way, this reduction valve can be turned out with a long beard (chub) without using the key. (Fig. 40)
Fig. 40. Raise the pressure in the TNVD housing by placing the reduction valve plug (1) (2) with a thin beard. As a result of these blows, the spring (3) is stronger than the plunger (4) and it will block the fuel reset hole (5). To return the plug back (reduce the pressure in the TNVD case), it is necessary to stronger the plug down stronger so that it squeezes the spring completely and pressed the plunger in such a way as to push the stopper (6). After that, the plunger and spring are easily falling out. Next, you need to flip the reduction valve and the thin beard is pushed back. Next, all collected in place and repeat the attempt to adjust the pressure.
There all seals are made on rubber rods (torics) and a strong tightening is not required. If this valve is a whole, its plunger is not flared in the open position, then the fault of the supply pump should be suspected. Provided that when driving fuel, the engine operation becomes smoother. True, if a fuel with air bubbles pour out from the engine of the overflow (reversal) during the engine operation, then first of all it is necessary to eliminate air seats. Because if there is a drowsing of the air, it is difficult to create the required pressure in the pump, even with the cavity in a good feed pump. But air sawmill problems are a separate topic. Here you just note that the air supply, even with external nutrition, i.e. When the fuel canister is above the TNVD, it is possible through the TNVD gland and through the density of the central plug on the cast-iron part of the pump. This plug is used to accurately install the fuel in the corner of the fuel (it is discouraged, the micrometric head is installed and the plunger's course is measured, this procedure is described in almost all WRD repair manuals). With a fully working TNTVD, even if it was previously delivered, after 10 minutes of engine operation in the overflow line no air bubbles.
So, the injection advance angle depends on the engine speed. To save fuel, the achievements of high power and in terms of ecology will be better if this advance angle will change taking into account and other engine conditions, such as the magnitude of the engine load, the pressure, temperature, and others. But fully accounting for all these conditions is possible Only at an electronic control. In conventional mechanical, only fuel pressure is taken into account in the TNLD housing and, on more modern units, the coolant temperature of the engine. The piston at the bottom of the pump moves depending on the pressure of the fuel and through a special steel "finger" slightly unfolds a profile washer (the same washer is forcibly turning the leash from the heating device mechanism). As a result, the wave protrusion of the washer will be used to run on the plunger, and he will start his movement earlier. This whole system was designed and made at the factory and badly coped with her duties. As long as the intensive wear has begun. He became intense because the fuel was not lubricating in the pump (our "dry" winter fuel, as well as kerosene, almost does not contain heavy fractions, which provide lubrication of all rubbing parts), fuel with air and just dirty fuel ( with abrasive). However, the usual old age also makes its business. As a result, the ledge on the washer begins to take a bit later to the plunger and he in turn starts a little later his movement. In other words, later injection begins. The beginning of this phenomenon looks like this. The engine works at idle and, due to the different wear of the nozzles, shakes a bit. Add turns to him. Approximately 1000 rpm engine stops shaking and as if freezing - it works Rovenko - Rovenko. Still raise the turnover. And suddenly in the range of 1500 - 2000 rpm appear shudder. These shudders (shaking) can appear both when smooth, but intense and during slow revolutions. During the shaking of the exhaust pipe goes blue smoke. When the engine is completely warmed, shaking around 1500 - 2000 rpm disappears. This is at the very beginning of the development of the defect. Then the shaking does not disappear after the engine warming up. Exactly the same shaking appears if you raise the injection pressure on the nozzles. In this case, if the TNVD is worn, the fuel injection will also be obtained. We get rid of this phenomenon, turning the TNLD housing to an earlier injection. Sometimes it is necessary to cranulate the TNLD almost until the stop. But before do it, listen to the operation of the engine. When the diesel engine has too early injection, it begins to work more hard (they also say that the valve is stared). And if you make sure the revolutions 50-100 before the start of the shaking this rigid component in the acoustic background of the diesel engine disappeared, it means that it is necessary to rotate the TNVD. It should be noted that there is a clearance of the worn diesel engines, the cylinder is very large and therefore they begin to work hard even with an absolutely right corner of the injection advance. The use of a stroboscope injection advance in our case is not entirely justified. We will not say that stroboscopes more confidently catch their microphone a knock of a very worn nozzle. If the nozzle is in a decent state, and the fuel supply tube is fixed again, the strobe lamp, as a rule, fails. Install using a stroboscope can be ahead of injection at idling. It is this advance that is given in the technical documentation. But wear in the TNVD uneven. And very often setting a lead by a label using a strobe when the idling turnover, we do not get rid of the shaking on the revolutions caused by the late fuel supply. Therefore, we recommend to put ahead of the rumor. With a wear that have a diesel engine exploited by us, this is a more acceptable way. After all, only in this way can be compensated by the late injection caused by low fuel pressure in the TNVD case due to wear of the feed pump. It is almost the same as the adjustment of the ignition advance of the gasoline. You can use the instruments to set the ignition advance only when the idle speed (and the other and not offered to repair manuals), but due to the malfunction, for example, the centrifugal regulator, will not go. It is clear that it must be fixed or changing. But you can, turning the rubber, put an acceptable ignition advance angle on the hearing. The only difference is that in gasoline engines the criterion for the installation of the ignition advance without the use of instruments will be detonation stuffs and engine power, and diesel engines are shaking, smoke and knobs in the engine.
It has already been mentioned above that most TNVD problems occur due to all kinds of leaks and leaks. I wear out, for example, the plunger, the leakage arose, so it does not create pressure. And if you replace the fuel is more dense? Then high gaps in the conjugated details would be less. And the pump will work as if he does not have any wear. Make fuel thick very simple. Add as stated above, in it any engine oil. Of course, I don't want to ride it - too expensive fuel gets (and it is troublesome, it is constantly prepared thick fuel). But for checking the state of the TNVD (as well as for the successful sale of a strongly used car in the bazaar), this reception is useful. In the cold season, we, because of natural laziness, in order to make fuel thick, simply cool the TNVD. For example, the car comes with a diesel engine with a complaint about what is badly started, if five minutes, but the engine is still hot. We start this car (indeed, sometimes you have to turn the starter of the seconds 30), warming it for another 10 minutes and the wasting. After that, we open it the hood and snow with a cooling pump. For the same 5 minutes. If, after this operation, the engine will start better than the first time, you can already talk about strong wear of the TNVD. Of course, both of these tricks (with thick fuel and cooling TNVD) are not described in the factory guidelines for repairing the engine and, so they cannot be considered very scientific. In those manuals, the fuel supply volume is measured at start-up (there is such a parameter in the technical data - the feed volume at a speed of 200 rpm) and check this parameter at home is also easy. To do this, you need to unscrew all the candles of incandescent and remove the tube with one nozzle. Then to wear a disposable medical syringe case on this tube and twist the engine. Naturally, counting "Pershika". 200 "PSHIKS", of course, a lot. It is enough and 50, and then the result obtained compare with the technical data. In this case, it can be assumed that the volume of injection at 200 rpm for all Japanese diesel engines if they have the same volume, there will be the same. If the volume of your engine is slightly different, it is easy to make a proportion with a diesel volume, the data to which you have. All this we also do it when the hot engine is badly started, although, as follows from practice, you can check everything and easier. Using snow and engine oil. In other words, if the operation of the TNVD with thick fuel becomes more acceptable, it is necessary to check the volume of injection. It is better, of course, it's all done on the stand (there you can check all the modes of operation in TNVD), but in the start mode (i.e., with 200 rpm), the test can be made in the garage.
So, if the diesel engine has shakes around 1500 - 2000 rpm, accompanied by the same blue exhaust gases, it is necessary to repair the fuel system. And in particular, to make fuel injection before. To do this, in the simplest case, you need to turn the pump to the earlier injection.
Kornienko Sergey, Vladivostok, Diagnostic
© Legion Autodata
From gasoline is the principle of diesel fuel. The ignition of the fuel and air mixture in the diesel engine is implemented by means of self-ignition of the diesel fuel from the contact with the previously compressed and heated as a result of such a compression by air in the cylinders.
Ignition on the diesel engine involves changing the fuel injection advance angle, which is served in a clearly specified point at the end of the compression cycle. If the angle is exhibited differently from the optimal parameters, then the fuel injection will be untimely. The result will be the defective combustion of the mixture in the cylinders, which causes a destructive imbalance in the engine operation.
It should be remembered that even minor deviations when placing the fuel injection angle can lead to a serious breakage of the diesel engine.
It turns out that under the ignition system of the diesel engine it is worth understanding the most important element of the power unit of the power unit. In most diesel engines, this device in a complex with diesel nozzles is responsible for the timely dosed supply of diesel fuel into the motor cylinders.
Read in this article
How to put an injection advance angle on the diesel
The need to install the ignition on the diesel engine often occurs in such cases:
- ignition of diesel, you need to adjust parallel to replacing the timing belt;
- after disassembling the pump, there is no possibility to install the fuel pump pulley according to special tags;
One of the recommendations before the start of any work related to the analysis of the diesel fuel equipment is the urgent need to make it clear and refresh all tags. To do this, it is enough to apply small strokes with the help of paint or high-quality marker. This will facilitate the subsequent reverse assembly and the installation of PTW pulley, which will automatically eliminate or minimize potential ignition failures.
Set the ignition on the diesel engine in several ways:
- strictly by tags (subject to availability);
- method of selection by experimental means;
Installing the corner
The first way to independently exhibit the ignition angle of diesel (the moment of injection of diesel fuel) by the labels implies the fuel pump displacement. This method is suitable for diesel engine, in which the mechanical fuel equipment is installed.
The injection advance angle is regulated by turning the TNLD around the axis. A method is also possible when the camshaft rotary pulley is rotated relative to the hub. This method is suitable for those designs in which the pump and pulley do not have a hard fastening.
- To adjust the ignition on the diesel engine, it is necessary to refer to the back of the engine and get to, if necessary, dismantle the protective casing from it.
- Next, it will be needed to detect the stopper on the flywheel, which goes into a special slot.
- After that, the flywheel must be wrapped manually (using a key or other device). Washing the flywheel means that the crankshaft is rotated. You need to twist clockwise until the top stopper will work.
- Then pay attention to the TNVD drive shaft. It is possible that the scale on the drive coupling, by means of which rotation is transmitted, occupies the upper position. In this case, the label on the flange of the TNLD is combined with a zero label on the drive.
- After combining the labels, the fastening bolts can be delayed. Frequently from the top position of the installation scale on the drive coupling means that the flywheel stopper must be raised, after which the engine crankshaft turns on one turn again. Next again controls the position of the scale.
- After tightening the bolts of the drive clutch, the stopper on the flywheel rises, the crankshaft rotates 90 °, then the stopper is accommodated in the groove.
The final stage is to install the protection of the flywheel in place and tightening the fastening bolts. Next, the engine is started, its operation is analyzed. The unit at idle should work smoothly and gently, without failures and twigs. The tough operation of a diesel engine, accompanied, is unacceptable.
Next, you need to check the correct setting in motion, avoiding serious loads. Heat the engine to operating temperature and evaluate the pickup of the power plant, the reaction to the press of the gas pedal. It is also necessary to monitor the color of exhaust gases, since the late fuel injection advance will be accompanied.
Selection of the right corner of injection
Configure the ignition angle on a diesel engine experimentally can be as follows:
- After installing the pulley, attempts to start a diesel engine. If the motor does not start, then the pulley of the TNVD turns relative to the belt for several teeth (2-4). Then the motor is trying again.
- The engine code after the manipulation described above has started, evaluate its work. The presence of obvious detonation knocks means that the pulley of the fuel pump should be turned onto the tooth or two in the opposite rotation of the side. The appearance of thick gray smoke can point to the late tap of injection. In such a situation, the pulley of the pump turns on one tooth in the direction of rotation.
The lack of positive shifts in the operation of the motor will require the implementation of the fuel pump spinning around the axis. By such turning, it is necessary to display the motor to the optimal mode of operation. The best option will be the work of a diesel engine in this mode when it remains quite a bit before the start of detonation. The detonation knocks themselves are well visible in the sound of the engine.
The second available method involves the following steps:
- Dismantling of the high pressure tube from the injectors of the first cylinder is carried out. On the removed tube you need to wear a clear plastic hose and arrange in a vertical position.
- After that, you can turn on the ignition and rotate the pump pulley. The pulley rotates as soft as possible, slowly and gently.
- Next, it is necessary to monitor the level of fuel in the tube and reveal the upper border.
- Noticing when the level of diesel fuel in the tube is the highest, on the pulley it is necessary to make a label.
- Then the labels need to set the crankshaft and distribution shaft of the engine.
After starting, the engine is estimated. In the case of determining the early or later angle of fuel injection, the setup operation should be repeated.
Read also
Symptoms to determine the correctness of the ignition advance angle. The consequences of incorrectly configured Woz, ways to place the ignition.
