The high pressure fuel pump, abbreviated as high pressure fuel pump, is an integral part of modern diesel engines. The injection pump is designed to supply fuel to the cylinders in strictly defined quantities during certain cycles of the diesel engine.
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Also, high-pressure fuel pumps can differ among themselves in varieties, pumps can be of the following designs:
If you do not go into the "wilds" of design differences between pumps of different types, then you can simply identify certain differences between them. In in-line and multi-section pumps, each section supplies diesel to its own cylinder. In distribution pumps, one "block" is capable of providing several cylinders with diesel.
Also, another difference between high-pressure fuel pumps is their “power” - how many cylinders the pump is designed for and its pressure. In general, these are all obvious differences between the pumps. In general, these are the main differences between pumps. Now we will no longer torment our readers with theories about the operation of high-pressure fuel pumps and their primitive characteristics, which have long been set out on the Internet in large quantities. Let's move on to the immediate specifics.
It is deliberately not indicated that the engine belongs to the Mitsubishi manufacturer. This is due to the fact that at the moment there are several derivatives of this engine. Accordingly, they have a minimum of design differences, and the injection pump is suitable for both engines.
To be specific, this is the same engine as the Hyundai D4BH, the pump for it is fully compatible with the 4D56T ICE (the differences between the 4D56 and 4D56T ICEs are insignificant, the “T” index indicates a turbocharged engine).
The pump itself for the above engines exists only one, manufactured by Zexel (aka Diezel Kiki), and now BOSCH. Yes, final suppliers and packaging may vary, but in the end, injection pumps for these engines can only be obtained by Zexel or BOSCH.
Basically, the accelerated exit of the high-pressure fuel pump on these engines is caused by low-quality fuel, as well as the ingress of foreign elements into the system, which often occurs with loose connections and driving over rough terrain, fords, etc.
Until now, disputes about which high-pressure fuel pump for 4D56 / 4M40 / D4BH engines are better, electronic or mechanical, have not subsided. How big are the differences in the injection pumps themselves and the attached electronics for the pumps. Is it important to replace the electronic fuel injection pump with a mechanical one?Let's take a closer look.
So, the main difference in this moment is not the pump itself, but the equipment (electronics or mechanics) that activates the fuel supply system, depending on one or another engine operating mode. In a mechanical injection pump, activation occurs due to the direct mechanical control of the injection pump. A cable runs from the gas pedal to the pump, which controls the system. In the electronic injection pump (EFI), the gas pedal is already electronic and the activation of the system occurs through related electronic units and sensors.
There is also a version about the existence of a cable drive for controlling an electronic high-pressure fuel pump (there is a control rheostat on the pump itself), however, our editors could not verify the accuracy of this particular information.
Before proceeding with the description of the process of removing the pump from the car, it should be mentioned that this article is not a guide to work on a specific car!
Zexel injection pump (aka Diezel Kiki or BOSCH) is equipped with a large number of cars with 4D56, 4M40, D4BH engines. Moreover, this family of engines is installed on completely different cars in terms of their characteristics and layout of units, such as Pajero Sport and Hyundai Starex, so attachments will differ in most cases. We will simply talk about the process of removing the pump in general terms, without delving into the design differences between cars of different brands equipped with these engines and pumps.
The pump has been removed, now, depending on the problems, it can be sent to the service to the master. Well, or do the repair yourself if the breakdown is not very serious.
Installation of the injection pump is carried out in the reverse order: installation of bolts, connection of vacuum hoses and electricity, etc. However, it is worth noting that when installing the pump, be sure to set the marks in the correct position! In addition, it should be remembered that the elements of the high pressure system must be installed using a torque wrench. We apply the tightening forces of each element during installation:
VIDEO
Once the assembly is completed, it is necessary to scroll the crankshaft pulley with a key and make sure that there are no extraneous knocks and rattles. Then you should pump the fuel and only then start the car.
Repairing a pump with your own hands is a responsible task that requires a large amount of knowledge, experience and the availability of your own equipment, therefore, before deciding to take such a crucial step, we strongly recommend that you weigh your chances. Yes, such simple maintenance as installing a gasket repair kit and cleaning the mesh filter is not so difficult, and you can do it yourself. But more serious repairs should be trusted to professionals.
As a test subject - a mechanical pump removed from the car and washed. One simple repair is to replace the shaft seal.
To do this, it is necessary to remove the injection pump drive pulley with a puller, then remove the old oil seal and install a new one. It is important to note that it is not necessary to press in a new oil seal deeply, its adjustment and position should not differ from how the previous one was installed.
Next - cleaning the mesh in front of the plunger pair. To do this, unscrew the 4 bolts on the body of the pump itself, remove the cover, simultaneously checking the mechanisms for backlash (they should not be), and carefully remove the plungers and blow through the mesh. Then install everything in reverse order.
The rest of the repair is more complex and requires certain skills, even to replace a complete pump repair kit. With a simple repair, it remains to be content with the repairs of the above consumables and the replacement of gaskets.
Attention, the editors of the site “Your Road” recommends consulting a specialist before applying this instruction to action.
One of the most mysterious components of a car with a diesel engine is rightfully a high pressure fuel pump (TNFP). There are 2 types of pumps - a mechanical pump and an electronically controlled pump, commonly known as EFI. Each of the types is divided into 2 subspecies: Multi-plunger in-line, single-plunger distribution type (VE). We will not consider “exotics” such as a pump-injector, Common Rail or Distribution pumps of the VR series (Distribution pump with an axial plunger, Distribution rotary injection pump)
Since the device, and therefore the principle of its operation, is a mystery to many, there is an opinion that specialized equipment and a specially trained person are needed to repair it. However, such a “gentleman's” set is not always at hand, so let's try to disassemble and assemble this tricky knot “on the knee”. An injection pump assembled in ancient times from several different types of pumps, without the use of stands, but at the same time successfully spinning a 4D56 diesel WITHOUT TURBINE up to 8000 rpm, will act as an object for preparation. Outwardly, it can differ from the high-pressure fuel pump installed on your car only in the absence of a pressure corrector (a kind of mushroom-hat on the top cover) and some mounted units. It does not change the essence of the matter.
So, on the table- OH.. Top view
The colored arrows indicate:
Green - fuel supply bolt
Yellow - "return"
Black - pressure valve in the injection pump housing
Red - axis of the fuel supply regulator (drive "gas"). The throttle lever itself has been dismantled for convenience.
Brown - bolt "quality" of the mixture.
The arrows indicate:
Black - automatic heating
Green - automatic warm-up drive
Red - automatic ignition advance (injection)
Blue - Identification plate
Side view (back side):
Blue - speed sensor (tachometer, not always present)
Red - fuel cut-off valve (silencer)
Yellow - pressure valve.
Green is actually a plunger.
Black - the axis of the fuel supply lever. The same one is on the back of the pump. To move (but not completely unscrew) them is better at the initial stage of disassembly.
For work you will need: a set of heads, a set of hexagons, tweezers, screwdrivers, a gas wrench, a caliper, a vice, a clean rag, a container with clean diesel fuel, grease (Litol, CV joint, etc.), well, the PRE-WASHED patient himself -))
A mesh filter is installed inside, which, as a rule, cannot be washed. Removal has no "contraindications" (yellow arrow).
It has a calibrated hole on the side surface (red arrow). Its size is different for different pumps, so replacing it with another one leads to a change in the internal pressure in the pump.
I don't think comments are needed. Tip - the drive itself should not be disassembled.
Yellow - speed sensor
Green - "silencer".
Black - centrifugal speed controller.
Blue - fuel supply drive lever.
There is one difficulty - to get to one of the 3 bolts. There are only two options:
Disassemble the drive (carefully, there is a powerful spring! + REMEMBER the setting of the adjusting bolt), and then calmly unscrew the rest.
Unscrew 2 “light” turnkey bolts “by 10”, loosen the 3rd, “heavy”, and moving the assembly away, slowly unscrew it.
It should turn out like this:
Yellow - o-ring
Red - automatic advance adjusting bolt
Green - the cover of the advance machine.
We remember (write down) the departure of the bolt head (red arrow) above the cover (green arrow). If in the process you decide to unscrew this bolt, during assembly you will need to return the dimensions to their original state.
Blue - the axis of the speed controller.
Black - mating plane.
Attention! For RIGHT rotation pumps, the thread on the axle will be LEFT and vice versa!
If you can pick up a tool, unscrew the pressure regulator.
Now the fun begins. The analysis includes nodes consisting of several parts. Moreover, the details cannot "live" without each other. That is, they simply cannot be confused with each other.
Red - pressure valve body
Green - return spring
Blue - valve needle
Yellow - valve seat
Black - sealing washer.
The plug under the red arrow can not be unscrewed, it serves to install the indicator. The fact is that the ignition on diesel engines is set not so much by marks. Rather, initially, the moment of injection is set according to the indicator, and only then the mark that we see is applied. We will omit this procedure for now, the turn will reach it.
So, unscrew the plug (blue arrow). This is where the gas wrench comes in handy. Plug thread - right hand.
Blue - plunger body
Red is a plunger.
At this stage, it is necessary to measure the amount by which the plunger sinks into the body. We record the results of the measurement, they will be useful during assembly.
Loosen the fixing screws (but not completely), and CAREFULLY shaking, move the plunger body up. As soon as it is released, we finally unscrew the screws and remove the plunger body. You should get this picture:
Blue - plunger
Yellow - dosing ring
Red - washer - bearing
Brown - base plate
Black - spring
Green - adjusting washers.
Black - plunger adjusting washer
Red - cam washer.
Green - fuel supply lever. I managed to take it off earlier.
Attention!! We do not remove the rollers, we do not change their places.
Remove the stopper (shown with a screwdriver).
Under the stopper we see the pin.It is also shown with a screwdriver (it is magnetized, the pin can be easily removed with it).
Remove the cam drive.
We push the axis of the advance automaton into the inside of the vacated space:
For convenience, I deleted 1 video, there is nothing criminal here. For the axis of the advance machine, we pull the roller ring out. Be careful not to overdo it! At the slightest misalignment, the ring jams in the body. Attempts to pull it out “insolently” will end deplorably - the pump housing will go to waste.
It should look something like this:
For the 2 “horns” sticking out in the bowels of the pump, we take out the pump shaft with the regulator gear:
We return to the "remains" of the pump:
We release the bolts (blue arrows) and take out the cover of the booster pump (red arrow).
Turn over the pump housing.
We remove the gland (shown with a screwdriver). Warning - do not try to save it, it will not work anyway.
As a result, a bare body with a sleeve pressed into it should remain. Here's one:
There is no more complex and responsible unit in a diesel engine than the fuel injection system, more precisely, its main part - the high pressure fuel pump. Many mating parts, highly loaded units, the presence of a precision dosing system make the repair of high-pressure fuel pumps a difficult task even in service conditions. It is all the more difficult to repair the high pressure fuel pump of a diesel engine with your own hands.
In automotive technology, almost everything is repaired, except, perhaps, individual oil seals and cuffs, the repair of which is impossible without special materials. The complexity of setting up, diagnosing and repairing high-pressure fuel pumps requires the employee to have skills in working with precision mechanics.
It is simply impossible to set up according to factory parameters, without a special diagnostic stand for repairing high-pressure fuel pumps. During the diagnostic study of the injection pump, it is necessary to check:
cyclic supply of the high-pressure pump, in the entire range of revolutions of the high-pressure fuel pump shaft, at start-up, and after cutting off the fuel supply;
stability of the developed pressure;
uniformity of supply of the injected high-pressure fuel pump to the fuel injector.
Even having access to a diagnostic stand, and having studied the issue of repairing a high-pressure fuel pump using numerous videos, it is very difficult to qualitatively check and evaluate its work.
In heavy diesel engines, plunger, in-line injection pumps are used. Such devices are more difficult to maintain and repair, since they require special equipment for disassembling it, so we will not consider such high-pressure fuel pumps and their repair.
In a passenger diesel engine, a distribution-type injection pump is almost always used. Unlike in-line, in a distribution pump, the force on the plunger is transmitted using a profiled cam. The design of the injection pump turned out to be more compact, but it is hardly easier to expect to repair it on the knee.
The most famous and affordable is the Bosh VP44 injection pump. Often, the need to repair the insides of the pump arises when:
poor traction and incomplete combustion of fuel even under ideal conditions - in the absence of load and a thoroughly warmed-up engine;
sudden failure and stop of the diesel engine under load, as they say, "death on takeoff." Usually the scanner in such cases diagnoses the code P1630 and P1651.
the appearance of a leakage of diesel fuel in the area of \u200b\u200bthe gland of the seal of the central shaft of the high-pressure fuel pump.
Therefore, we will limit ourselves to the issue of repairing high-pressure fuel pumps with our own hands by replacing seals and eliminating scuffing of the working surfaces of parts.
Before disassembling the injection pump drive shaft seal, try to move it in the radial direction. If play is felt by hand, the cause of fuel leakage may be the wear of the working surface of the shaft or the bearing needs to be repaired.
A large number of split planes and mating surfaces of parts required the use of a large number of seals and seals. As a rule, they are made of high-quality material and serve for a long time until they are damaged during repair or maintenance. In this case, for do-it-yourself repair of the Bosch injection pump, standard repair kits are used.
It is enough to simply replace the seal on the shaft position sensor and on the injection advance control during repair. For a better fit on new rings and rubber bands, you can drop a couple of drops of spindle or engine oil.
For preventive repair of the Bosch injection pump with your own hands, you will need to disassemble the pump in approximately the following order:
remove the metering valve from the end part of the injection pump. To do this, unscrew the four screws of the pressure plate, carefully release the injection advance valve cable. After removing the three screws securing the metering valve, you can carefully remove it from the socket;
by unscrewing the mount on the top cover, you can remove the control board and gain access to the electronics;
set the position of the shaft, as shown in the photo, remove the camera and get access to the insides of the injection pump;
after dismantling the bearing with the help of a special puller, we get the opportunity to study the potential culprit for the poor performance of the injection pump - the piston of the injection advance unit. Often there is surface wear and tearing on the edges on the part. You can try to repair the surface by polishing, replacing the entire part is much more expensive.
After repair, the assembly is carried out in the reverse order with washing the parts with diesel fuel.
Often, in addition to scuffing, there is another reason on the surface of the pistons why the injection pump does not develop the necessary pressure. This may be caused by debris, films or wax build-up deposited on the filter screen inside the pump. There is a mesh on the side of the inlet pipe. Flushing the channels is troublesome and inefficient, it is easier to remove the mesh and blow it with compressed air.
Broken pieces of debris can jam the plunger piston or even cause the pump drive shaft to break or break. Therefore, cleaning should be carried out very carefully to avoid contamination of the internal cavities of the pump.
Among the many reasons for the failure of the electronic “liver” of the high-pressure fuel pump, the breakage or burnout of the contacts of the control board and the failure of power transistors are more common than others. If the knowledge and skills of working with electronic devices allow you to “diagnose” the performance of transistors and repair, you should try to identify the cause and replace the culprit with a serviceable element.
To check the condition of the “culprit”, you need to carefully open the black cover, tightly seated on the rubber seal with screws. It should be removed carefully so as not to damage the seal itself.
The reason for the failure of not only the transistor, but the entire board could be air that got into the cavity due to poor performance of the drainage system or a check valve. Often they try to eliminate airing by spinning the starter, hoping to pump diesel fuel into the high-pressure fuel pump in this way. At this moment, the transistor is open and loaded to the maximum, which leads to intense heating. In an air environment with poor heat dissipation, it will inevitably burn out. In some German cars, there is protection that prevents an attempt to start the engine in the absence of fuel in the line. To do this, use the fuel sensor in the tank.
The failure of the transistor can be established by a "dialing" tester or by appearance. The best option for repairing such a malfunction would be to replace the entire control board. Perhaps this is more expensive than soldering, but it will give guaranteed quality and stable operation of the high-pressure fuel pump after repair. As a last resort, give the board and transistor for soldering to specialists - electronics engineers.
When installing and reassembling after repair, check the tightness of all fasteners.
If during the revision process you did not make rash and unreasonable replacements of parts, the assembled pump should work with approximately the same parameters as before. As a standard, for testing and adjusting the injection pump after a major overhaul, use the Bosch EPS-815 stand.
On the video you can learn how to increase the plunger pressure in the Bosch VE injection pump:
VIDEO
“Diesel Market ” – Engine parts: pistons, rings, liners, gaskets, sprayers, spark plugs, plunger pairs, injection pumps
AUTOWELT – spare parts for engines of Japanese and European cars
DENSODIESEL – central distributor of DENSO for diesel injection systems in Russia
Cold smoke is usually bluish, the main reason for the appearance of smoke due to candles is the correct operation of the candles for these engines, which is about 14 seconds. heating then starting, and after that the candles keep heating for some time until the engine warms up for its stable operation. In your case, most likely one of the candles does not work, or it does not have full heating, or it is not correct (that is, the heating is not of the tip of the candle, but of its middle - this is all easily checked)
As we noticed, if driving without a balancing belt suits you, then there is nothing to worry about, usually its absence causes a slight vibration at idle, and a rumble when driving from 90 km / h more
A slight breath is permissible, after all, the engine is not new, the consumption of diesel fuel for the city is normal, as a rule, oil seals leak (unless, of course, it does not affect oil consumption with a roach), but it would be better if there were no leaks!
Cars change, friends and the forum remain. [my.housecope.com/wp-content/uploads/ext/1209]
Message Sergey27 » 14 Jul 2009, 14:05
Message Shadow from Omsk » 14 Jul 2009, 14:30
Message Sergey27 » Jul 15, 2009, 04:09 PM
Thanks for the help.)
Message Shadow from Omsk » 15 Jul 2009, 17:19
Message Sergey27 » Jul 16, 2009, 04:16 PM
Message Shadow from Omsk » 16 Jul 2009, 19:12
It seems to me that the mechanic screwed up, and very much.
1) Blue smoke - poorly burning diesel fuel, this is partly indicated by the difficult rotation of the engine by the sterter, it is possible that early injection. As an option - check how easily the engine rotates when the ignition is off, for example, for snoring, try to crawl from below. If it rotates tightly, it means that the main bearings have been overtightened, and maybe there are problems with the connecting rods. If it rotates easily, turn on the ignition, rotate the engine with a ratchet, if it is jerky, at first it is easy, then an effort that is difficult to overpower increases and then again easily, most likely early injection.
2) An overhauled engine will not be thrown and SHOULD NOT be thrown. oil through the breather. For lapping rings, 5 hours at XX is enough. Measure the compression, measure the compression drop time. How are the valves adjusted? Did you grind? Is the injection advance angle set by eye?
There is only one conclusion, extremely unpleasant. Either during the assembly process, they maliciously messed up with the installation of parts, or parts with poor quality or fit were installed.
Message kutum » 15 Aug 2009, 13:11
Message Slk 79 » Jun 03, 2010, 19:31
Message grandfather » Jun 04, 2010, 06:32 pm
Message dyumin » Jun 04, 2010, 22:10
Added after 1 minute 45 seconds:
T The high pressure oil pump is a very important unit. The injection pump shaft is driven by a timing belt. The high pressure fuel pump has many tasks and functions. Here are the main ones:
one.High pressure fuel supply to injectors;
2. Change in the amount of injected fuel per unit of time at different crankshaft speeds;
3. Fuel cut-off by solenoid valve when the engine is stopped;
4. Taking readings of revolutions (for a tachometer, etc.);
5. Correction of the amount of injected fuel when the turbine reaches operating speed (by vacuum);
6. Warm-up control (at low coolant temperature, fuel supply increases);
7. Management of the number of idle speeds (XX) in connection with the inclusion of the air conditioner, refrigerator (vacuum).
Also, the minimum speed of the XX is adjusted, the maximum engine speed is limited. Adjustment of the nominal fuel supply, ignition timing ...
To replace the rubber O-rings, we release the injection pump regulator lever. We unscrew 4 hex screws (5mm) indicated in the figure on the left (pos.1).
2 - Vacuum actuator for increasing the speed of the XX due to the inclusion of a refrigerator, air conditioner or a button to increase the speed of the XX.
3 - Warm-up control (adding speed at low coolant temperature).
4 - The lever of the fuel supply control regulator.
1. The heating control device is disconnected from the injection pump by unscrewing the three bolts;
2. O-ring at the point where the control lever enters
3. Internal arm; establishing an earlier injection;
4. Setting the speed during warm-up;
5. Speed boost lever, outside;
6. Connecting the temperature sensor to the coolant circuit .
1. Cover of the corrector for boost pressure;
2. The regulator lever seal, it is from this place that fuel sometimes leaks;
3. The screw for adjusting the nominal fuel supply, after adjustment on the stand, is sealed. If you uncheck it, it is possible to change the cyclic fuel supply with an adjusting rod, - by unscrewing it - we reduce the supply, by screwing it - we increase . Without knowledge and experience, we do not recommend touching it, since there is a high probability of the engine stalling, increasing smoke, and poor deceleration. If, nevertheless, when adjusting on a running engine, you overdo it, and the engine starts to gain momentum, immediately unscrew this screw a couple of turns back.
In this place, indicated by the arrow, the regulator shaft engages with the regulator levers. The regulator shaft is removed from the lever system precisely through this groove, which allows you to disconnect the top cover from the injection pump housing (shown in the figure below).
Carefully remove the axis of the regulator lever from the injection pump cover. In case of fuel leaks, as well as after disassembly, it is imperative to change the annular rubber seal ring on the regulator axle and the stuffing box installed in the injection pump cover in the place where the regulator axle comes out.
Consider the operation of a high pressure fuel pump.
Turning the injection pump with the drive down, remove the unscrewed head of the fuel pump. This is done so that the springs, rollers with washers do not get enough sleep.
After all, each part has its own run-in place, this must also be remembered and everything must be laid out correctly when disassembling, so that later it can be correctly assembled. In the picture on the left, the yellow arrows show the rollers with washers (mounted on the outside of the roller, and the roller washers should face the rollers with a flat surface). Each roller is in its seat, it is they who are subject to strong mechanical stress, and on “running basses” they have significant output.
Care must be taken when removing the clip with rollers so that they do not fall out! And you can’t change the location of the rollers in the cage, this also applies to washers.
From the timing belt, the torque is transmitted to the cam washer through an adapter (coupling with a spring).
The spring-loaded mechanical contact causes the plunger to move forward along its axis and at the same time also rotate. Numerous channels are located in the injection pump head, and the pump plunger has slots and through holes in its lower part. Thus, at a certain position of the plunger, the distribution of fuel occurs at the outlet of the injection pump head.
As you can see from the figures on the left, in the upper end part of the injection pump head there is a fuel shut-off solenoid valve
This valve can be removed and separately tested by applying voltage from the battery (+ to the contact, - to the valve body). A characteristic click will be heard and the valve will be drawn into the core. Thus, when voltage is applied to the cut-off valve, the fuel supply channel opens, and when the voltage is removed, the fuel channel is blocked with a rubber seal under the action of a locking spring. This locking principle is used in our vans to stop the engine. Without voltage supply to this valve, it is impossible to start the engine, even if everything is in perfect order. This method is used by many anti-theft systems that are part of the alarms, built into the break of this control wire.
Pictured left
1. Solenoid valve body;
2. Positive contact of the electromagnet coil (negative is fixed on the valve body);
3. Mesh filter installed at the plunger inlet.
As you can see, dirt that has passed with fuel even through the main fuel filter settles on this small filter, and somewhere there is lint from the filter itself. This filter prevents other debris at the fuel inlet from entering the plunger, thereby preventing rapid wear of precision surfaces from small debris.
To get this filter out of the recess in the injection pump head, I advise you to use tweezers.
Solenoid valve; Rubber O-ring; return spring; Core - valve; Rubber seal; Fuel filter mesh in the injection pump head. Unfortunately, on the high-pressure fuel pump installed on the engine, access to this valve and filter is difficult, however, you will know about its location there! And if the fuel is supplied with difficulty, especially in winter, this is pronounced, you should ask a specialist to clean this filter mesh at the service.
Installed tachometer sensor;
Regulator weight holder assembly;
Head-mounted injection pump, fuel shut-off solenoid valve
On the right you see the tachometer inductive sensor. It is made sealed. A solenoid is installed inside (coil resistance is from 600 to 950 ohms, if there is an open in the sensor circuit, or the resistance does not match the above, the sensor should be replaced). Consider the principle of operation of the speed sensor. The gear on the weight holder rotates and each tooth of this gear, approaching the working surface of the sensor, induces
in the EMF coil. This is how a series of pulses, depending on the speed of rotation of the crankshaft, enters the microcontroller for processing, and from there comes the information that is familiar to our eyes.
Let us consider in more detail the principle of operation of the idle speed increase system (XX), when the engine is warming up, and when the air conditioner is turned on. The figure on the left shows a picture of the interaction of levers on the injection pump regulator:
1. Vacuum actuator controlled by vacuum when the air conditioner is turned on or the XX speed increase button;
2. A thermoelement that acts on the levers depending on the temperature of the coolant in the system and sets an earlier injection angle;
4. Intermediate lever with adjusting screw.
When the air conditioner is started, a signal is given to turn on the vacuum switch, the vacuum through the rubber tube reaches the membrane of the vacuum actuator 1 (in the figure above), as a result, the pusher is retracted in the direction indicated by the arrow in the figure, acting on the intermediate lever 4.That, in turn, through the adjusting screw presses on the regulator lever on the high-pressure fuel pump, thereby increasing the speed of the twentieth until the air conditioner is turned off.
Now consider how the engine warm-up is implemented. The coolant (coolant) passes through the thermoelement 2. Depending on the coolant temperature, the thermocouple rod changes its position along the axis within 8-10 mm. Thus, it is very easy to check the disconnected thermostat, it is enough to substitute it under a stream of hot water or dip the side of the tubes into boiling water, and its stem will extend by about a centimeter.
The figure on the right shows the direction of movement of the stem depending on the state (cold or hot). This is what happens when you start a cold engine. The stem of the thermoelement is pulled inward as much as possible, allowing the strongly twisted spring coil to act on the intermediate lever 4 (in the figure above). In addition, on the inside of the injection pump housing, the lever sets an earlier injection advance angle until the engine warms up. As it heats up, with an increase in the coolant temperature, the thermoelement rod extends, neutralizing the action of the spring, up to the complete elimination of the effect on the intermediate lever and returning the injection angle to the working position.
The force of the spring on the stem can be adjusted with screw 1 (in the figure on the right), after adjustment, tighten the lock nut. The free play in the lever system is removed using the adjusting screw on the intermediate lever 4.
Thus, the adjusted system will, when starting a cold engine, increase the speed to 1000-1100, and drop them gradually to 850 when the engine is fully warmed up.
For clarity, I’ll give a picture that will show the principle of operation of the automatic heating and injection advance:
Positions 1,2 and 3 indicate the installation sites for high-pressure fuel pump fine filters. Often pile accumulates there from low-quality fuel filters. In the hollow bolts at the fuel inlet to the injection pump and the return outlet (pos. 1 and 2), metal meshes are rolled (or cored), which should be blown with compressed air and washed, or disassembled and cleaned.
Video (click to play).
We carefully remove the mesh under the cut-off valve with tweezers, before that, the terminal with the wire on top is unscrewed and the valve is unscrewed. Be careful, do not overdo it with tightening the valve contact, excessive force can destroy the insulator. Under the number 5, the minimum idle speed bolt (XX) is shown, when the engine is warm and the effect of the warm-up machine is removed through the bolt (pos. 4), the regulator lever plate must lie completely on the bolt for limiting the minimum speed XX (for automatic transmission - 850 rpm, for manual transmission 700..750 rpm), the IDLE UP key must be in the OFF state.
