The adjustment of the plunger pairs to the same stroke and the same amount of feed, as well as the adjustment of the speed controller and the injection advance device (clutch), are carried out on a special test bench for high-pressure fuel pumps. These stands are equipped with all necessary measuring devices and variable speed drive. The instructions for repair and checks on the test stand, together with the necessary data, contain all the information necessary for repair and service work.
Adjustment of injection pump on the engine
The high-pressure fuel pump is synchronized with the engine using setting marks to start injection (closing the channel). These marks are located on the engine and on the injection pump.
Typically, the engine compression stroke is used as the basis (reference point for injection timing adjustments, although for specific model engine, other possibilities can be used). For this reason, it is important that the manufacturer's instructions are followed. In most cases, the installation mark for closing the channel is located on the engine flywheel, on the pulley v-belt or vibration damper. There are several possibilities for adjusting the injection pump and setting the correct value for the start of injection (closing the channel).
- The injection pump is delivered from the factory in this form, when its camshaft is locked in a predetermined position. After installing the injection pump on the engine and strengthening it with bolts, when crankshaft is in the appropriate position, the injection pump camshaft is released. This well proven method is inexpensive and gaining more and more popularity.
- The injection pump is provided with a channel closing indicator at the end of the regulator, which must be aligned with installation marks when the injection pump is installed on the engine.
- The device (clutch) for advancing the moment of injection has a mark for closing the hole, which must be aligned with the mark on the injection pump housing. This method is not as accurate as the two previously described.
- After the injection pump is installed on the engine, the overflow method is used high pressure on one of the pump outlets to determine the point (moment) of closing the channel (i.e. when the plunger closes the fuel outlet channel). This "wet" method is also being actively replaced by method 1 and 2 described earlier.
Rice. High pressure fuel pump adjustment
Rice. Bleeding air from the fuel injection system
Air bubbles in the fuel can impair the operation of the injection pump or even make it impossible. In this regard, devices that are installed for the first time or temporarily switched off must be free from air.
If the fuel priming pump is equipped with a manual pump, then it is used to fill the line, fuel filter and fuel injection pump. The vent screws (1) on the filter cover and on the injection pump must remain open until the escaping fuel contains no bubbles. Bleeding must be done every time the fuel filter is replaced or any work is done on the system.
During real-world operation, the injection system is vented automatically via the overflow valve (2) on the fuel filter (permanent ventilation). A restrictor can be used instead of a valve if the pump does not have an overflow valve.
Rice. High pressure fuel pump lubricant
The injection pump and regulator are best connected to the engine lubrication system, because with this form of lubrication, the injection pump remains maintenance-free. filtered engine oil is supplied to the high pressure fuel pump and the regulator through the discharge line and the inlet channel through the hole of the roller pusher or using a special oil supply valve. In case of injection pump with base or frame, lube oil is returned to the engine via the return line (b).
In the case of flange mounting, the lubricating oil return can be through the camshaft bearing (a) or through special channels. Before turning on the injection pump and governor for the first time, they must be filled with the same oil as the engine. In case of injection pump without direct connection to oil system engine, oil is poured in through the cap after removing the cap to remove the air or filter. The oil level in the pump is checked by removing the oil level screw on the regulator at the intervals prescribed by the engine manufacturer for changing the oil in it. Excess oil (increase in quantity due to oil leakage from the lubrication system) must be drained, and if there is not enough oil, then add fresh butter. When the high pressure fuel pump is removed or when the engine undergoes major repairs, then lubricating oil need to replace. To check the oil level, injection pumps and regulators with a separate oil supply are equipped with their own dipstick.
Disabling injection pump for a long time
If the engine, and therefore the injection pump, remains unattended for a long time, then no diesel fuel should remain in the injection pump, because. over time, it becomes thick and viscous, plungers and delivery valves can seize and even corrode. For this reason, before conservation, you need to add about 10% suitable remedy against rust into the fuel tank and in the same proportion into the oil into the camshaft chamber of the injection pump. The engine should then be run for about 15 minutes, during which time all the normal diesel fuel will be flushed out of the injection pump, which at the same time will be effectively protected from fuel thickening and corrosion. New injection pumps that have already been effectively protected against corrosion at the factory are marked with the letter "p".
The high pressure fuel pump is technically important element system that provides fuel injection to a diesel engine. The pump delivers diesel fuel at the right pressure and in the right quantity. Simply put, the injection pump is responsible for providing fuel system fuel and its proper circulation.
Varieties of injection pump
High pressure fuel pumps are separated by the method of fuel injection. It can be produced by a battery injection system or using a plunger. The main element of the pump is such a part as a plunger pair, which visually represents a piston with a cylinder. Fuel is supplied inside the cylinder. Then it through inlet valve pushed out by the plunger. IN various techniques Several structurally different pumps are used:
distributive. The design of the unit has one or a pair of plungers that pump fuel through the cylinders;
in-line. These pumps structurally have only one plunger;
trunk. This pump pumps fuel into the battery.
Any equipment, even imported and the most reliable, can fail. As a rule, the earlier a breakdown is detected, the more inexpensive means it can be solved. If the repair procedure is not performed immediately, then a failed pump element can affect the working mechanisms of the entire power unit, and this breakdown will lead to a major overhaul. Each manufacturer establishes a certain period of operation in the passport and, subject to the rules of operation and terms technical inspection the need for overhaul may not occur. If we neglect the timing and the need for periodic inspection and operate the car even if a malfunction occurs, it will not reach the period recommended by the manufacturer and will require expensive overhaul.
The most common faults
Most often, the following malfunctions occur in TNVD:
mechanical pump. This malfunction is natural and occurs over time. More often, wear can occur when the car has been used with increased loads. Breakage manifests itself increased noise engine at startup uneven work, the impossibility of starting it in a hot state and reducing power;
malfunction due to the use of fuel Low quality. Since the fuel is the lubricant for the pump, its purity is the basis for the long-term operation of the unit. The fuel must not contain impurities in the form of small mechanical particles, water or gasoline, as they cause the device to break down;
the manifestation of a malfunction of the high-pressure fuel pump may affect the electronics of the car. Devices start to work incorrectly or turn off spontaneously.
Repair of high-pressure fuel pumps is often carried out by preliminary disassembly of the unit with the replacement of worn parts. For disassembly and subsequent collection, you will need the minimum amount of tools that are available in the garage of any motorist. If there is no necessary knowledge on the application device, it is better to entrust the repair to car service specialists.
High pressure fuel pump adjustment
Periodically, each high-pressure fuel pump needs to carry out an adjustment procedure. It is quite possible to make it yourself if you have the necessary equipment. Professional adjustment of the injection pump is carried out on special adjustment stands, which are not equipped with private garages. First, the metered fuel injection advance clutch is removed from the high-pressure fuel pump, then the camshaft is coupled with the drive device, which is located on the stand. Next, the verification and adjustment process itself starts, which reflects the uniformity of the fuel supply, as well as the volume of fuel supplied. The moment of fuel supply is also determined. All indicators are compared with the reference ones and recorded. The fuel timing adjustment process is used special device- momentoscope. In order to adjust the feed moment correctly, it is necessary to determine the place where the adjusting bolts screwed into the plunger pushers will be screwed.
As you can see, in order for the high-pressure fuel pump not to fail within the time strictly allotted by the manufacturer, it is the timely conduct of the adjustment procedure, as well as the quality of the fuel used. To ensure proper quality lubricants you will need to purchase oils recommended by the manufacturer, as well as timely replacement of the appropriate filters that control the purity of the oil. With knowledge of design features devices, it is quite possible to do all the work yourself, but carrying out these works by specialists will provide high quality activities, as well as tight deadlines. Also, such an approach will ensure the error-free activities, since the adjustment on their own will not provide the required accuracy.
TO category:
Repair fuel equipment cars
Checking and adjusting the high pressure pump
During the operation of a high-pressure pump, its main parts wear out: sleeves and plungers of the discharge sections, discharge valves, camshaft, pushers and other parts.
The wear of the discharge valves affects the nature of the injection, worsens the fuel cut-off by the injector, causes it to leak through the atomizer and coke the nozzle holes. The quality of the fuel supply also depends on the elasticity of the springs of the pushers, the tightness of the fittings, fuel supply lines and other reasons.
In order to reliably determine malfunctions and violations of the high-pressure pump adjustments, it is dismantled from the engine and checked at the SDTA-1 stand. The automatic injection advance clutch is removed from the pump and installed on the stand, engaging the stand drive shaft with the cam shaft through the coupling.
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In the process of testing the pump on the stand, the start of the supply, the amount and uniformity of the fuel supply by individual sections are checked and adjusted. In this case, the available on the stand is used automatic device to drive the shutter, which is inserted between the reference nozzles and measuring cylinders at the moment of turning off the supply, blocking the flow of fuel into the cylinders.
Excess fuel injected by the nozzles when the pump is stopped flows into the collection tray, and from it into the lower tank of the stand.
The number of fuel injections during testing is measured by a counter.
The start of supply is adjusted using a momentoscope (Fig. 87), which is a short segment of the fuel line connected by a rubber tube to a glass tube. The torque scope is connected to the fitting of each discharge section of the pump in turn, taking into account the order of operation of the engine cylinders. Sections are counted from the pump drive side.
To determine the start of fuel supply by each section of the pump, a disk is installed on its housing from the drive side, calibrated in degrees of rotation angle with divisions through 1° from 0 to 360°. On coupling The shaft of the pump drive is fixed with an arrow, which serves to count the rotation of the shaft.
The procedure for checking the start of filing is as follows. The high-pressure fuel line is disconnected from the fitting of the first discharge section and the momentoscope is fixed on it. By rotating the camshaft of the pump, the glass tube of the momentoscope is filled with fuel up to half the volume and the position of the camshaft is found, which will serve as the starting point for counting the angles of rotation. This position coincides with the start of fuel supply by the first section.
The beginning of the feed by the first section should occur when the cam shaft rotates and the cam runs on the pusher 38-39 ° to the axis of symmetry of the cam. To set the axis of symmetry of the cam of the first section, mark on the graduated disk the moment when the fuel level begins to move in the momentoscope. To do this, slowly turn the shaft clockwise and mark on the disk the angle of rotation, which coincides with the beginning of the fuel level moving up. Then rotate the shaft further clockwise through an angle of 90°.
Upon reaching an angle of 90 °, the shaft is stopped and slowly rotated counterclockwise, again observing the fuel level in the momentoscope. As soon as the fuel begins to move up again, note the resulting angle of rotation.
The fixed angle values allow you to determine the axis of symmetry of the cam. It passes through the middle between the marked points of the angles on the graduated disk and the axis of the camshaft. After that, setting an angle of 38-39° from the axis of symmetry counterclockwise along the disk, you can find the moment when the first section of the pump begins to feed. This position of the camshaft is conditionally taken as the origin, and the start of supply by the remaining sections of the pump is determined in degrees of rotation of the camshaft relative to the first section.
Rice. 87. Mo-mentoscope connection diagram:
1 - glass tube, 2 - rubber tube, 3 - fuel line, 4 - nut
To adjust the moment of the start of supply, adjusting bolts are used, screwed into the pushers of the plungers of the discharge sections of the pump. When the bolt is screwed in, the plunger will drop lower and later block the inlet of the sleeve, i.e. injection will begin later. The angle between the start of feed and the axis of symmetry of the cam will decrease.
When unscrewing adjusting bolt injection will start earlier and the angle will increase accordingly. After adjustment, the pusher bolts are locked with nuts and the angle of the fuel pump is checked again. If necessary, repeat this adjustment.
The uniformity and amount of fuel supply by the discharge sections of the pump is checked on the stand SDTA-1 by measuring the amount of fuel supplied by each section through the reference or pre-adjusted nozzles. At the same time, on the stand, you can check and adjust the speed controller crankshaft.
These works are performed in the following sequence:
a) at a pump camshaft speed of 1050 rpm, check the fuel pressure at the pump inlet, which should be 0.13-0.15 MPa;
b) check the minimum speed of the cam shaft in the position when the lever (Fig. 88) rests on the bolt. The indicated position corresponds to the full extension of the rail and the shutdown of the fuel supply by the regulator. In this case, the camshaft speed should be 225-275 rpm. To reduce the speed of rotation, the bolt 8 and the screw are unscrewed, and to increase, they are screwed in;
c) check the beginning of the automatic reduction of the fuel supply by the regulator by moving the rack. It should start at 1060 + 10 rpm and end with an increase in the speed of rotation to 1120-1150 rpm of the pump camshaft. The beginning of the extension of the rail is regulated by a bolt when the feed control lever rests on it. If the end of the extension of the rack does not stop at the required frequency, then, by changing the position of the screw of the two-arm lever, set the start of the rack movement to the required frequency of 1160 rpm with a bolt. Then the speed is checked again at the end of the rack extension and, if necessary, re-adjusted. In this case, it should be borne in mind that, by wrapping the screw, the rotational speed is reduced at the end of the rack movement, and when unscrewing, it is increased;
d) check the amount of fuel supply by each section of the pump. To do this, set the frequency of rotation of the cam shaft 1030 ± 10 rpm and the lever is moved all the way into the bolt. As soon as the required mode is set, an automatic device is turned on, which removes the shutter from under the nozzles and ensures the flow of fuel into the graduated cylinders for required amount injections. After a predetermined time, the machine turns off the supply and the injected fuel is collected in the measuring cylinders.
e) check the travel of the rack from the extreme extended position at 1030 ± 10 rpm of the camshaft of the pump when the lever is moved all the way into the bolt. The normal stroke should be equal to 13 ± 0.2 mm, and adjust it with a screw;
f) check and, if necessary, adjust the amount of starting feed, which at 80 ± 10 rpm of the camshaft should be 17-20 cm3 / min. Adjust the amount of feed with a screw: when the screw is screwed in, the feed decreases, when it is unscrewed, it increases.
Rice. 88. Adjusting devices in the engine crankshaft speed controller:
1 - speed limit screw for the break-in period, 2 - starting feed adjustment screw, 3 - corrector lock nut, 4 - feed adjustment screw, 5 - two-arm lever screw, 6 - buffer spring screw, 7 - maximum speed limit bolt, 8 - minimum speed adjustment bolt, 9 - control lever
The amount of fuel supplied by the injection section depends on the position of the helical edge of the plunger relative to the drain hole of the sleeve.
In order for all sections to supply the same amount of fuel, it is necessary to ensure the same active stroke of the plungers, i.e., the opening of the drain holes in all sections must occur in the same time interval. This is achieved by turning the plunger associated with the rotary sleeve in relation to the ring gear while loosening the pinch screw. Turning the sleeve to the left causes a decrease in the fuel supply, turning to the right increases the supply.
Turning off the fuel supply is checked by turning the stop bracket to the lower position. If the feed does not turn off, check the progress of the rack, inspect the backstage and troubleshoot its drive. This completes the adjustment of the pump on the stand.
After checking and adjusting, the pump is removed from the stand, an automatic injection advance clutch is attached to the toe of the camshaft and the pump is installed on the engine.
When installing the pump in the camber of the engine cylinders, the marks on the driving flange of the drive shaft, the driven coupling half and the injection advance coupling are combined, the drive coupling halves are rigidly connected in this position and the pump is fixed to the engine. Next, collect the highways of high and low pressure, set the fuel injection advance angle, start the engine and, after warming up, regulate its idling.
A high-pressure fuel pump or, as is often found in specialized literature and the Internet, high-pressure fuel pumps, is one of the important and rather complex components, like all diesel engines, and still a small part gasoline engines- those of them in which direct fuel inlet into the combustion chamber is carried out.
Device, principle of operation and types.
From the name of this unit, it can be understood that its main task is to supply high-pressure fuel to the engine (if you imagine work, then fuel is supplied through the nozzle with this pressure directly into the combustion chamber, where in this moment contain compressed air).
Types of high pressure fuel pumps.
Because of this task, the high pressure fuel pump is sufficient complex mechanism. At the same time, the structural design High pressure fuel pump is divided into how many types:
- row type,
- distribution type,
- main type.
What are their differences?
The first two types are very similar in design.
In-line high pressure fuel pump (photo).
Distribution type high pressure fuel pump (photo).
They are based on a plunger pair (cylinder and rod), teamwork which, driven by the crankshaft through a cam mechanism (shaft), creates required pressure fuel. The only difference is that in an in-line fuel pump, the number of plungers is equal to the number of engine cylinders, respectively, each plunger serves its own cylinder. But in the fuel injection pump of the distribution type - no. For example, on a conventional 4-cylinder engine with a distributive type fuel pump high pressure, you can most often find a 1-plunger mechanism that serves all cylinders. The system works in such a way that at a certain point in time the plunger supplies the required portion of fuel under pressure to the corresponding cylinder.
High pressure fuel pump device of in-line type.
- pressure line fitting
- valve seat
- valve spring
- pump section casing
- discharge valve
- inlet and outlet
- inclined surface of the plunger
- plunger
- sleeve
- plunger control lever
- return plunger spring
- pusher spring
- roller pusher
- cam
- rack
Distribution-type high-pressure fuel pump device.
- fuel regulator drive gear
- fuel inlet
- fuel outlet
- adjusting screw
- solenoid shutoff valve
- distribution block
- pressure pipe fittings
- plunger-distributor
- cam washer
- video clip
- vane fuel priming pump
- flange
Which one is better? - it’s hard to say, since pumps of both in-line and distribution types have their own unique advantages: an in-line injection pump due to a lower load on each plunger has more long term service, but the distribution type system creates a more uniform fuel supply.
Fuel pump of a high pressure of the main type (photo).
Now let's move on to the high-pressure fuel pump of the main type. This type fuel pump, or rather the entire fuel supply system is sometimes found under the name “ common rail". Its main difference from the previously considered types is that the fuel is pumped under pressure here not into the combustion chamber, but into fuel rail(battery). From there, the fuel is distributed to the cylinders. The moment of injection is controlled by an electromagnetic nozzle, which opens on command on-board computer. The injection pump itself used in such a system may have one or more plunger pair and driven by the crankshaft.
High-pressure fuel pump device of the main type.
- drive camshaft
- video clip
- plunger spring
- plunger
- Pressure line fitting (to fuel rail)
- Exhaust valve
- inlet valve
- fuel metering solenoid valve
- filter fine cleaning fuel
- bypass valve
- fuel return fitting
- fuel inlet fitting
Concluding the overview of the types of injection pumps, we can also note the fact that both of the first types of fuel pumps are inherently purely mechanical components. Their work is based on the application of mechanical laws and can work without the use of electronic components at all. The system with the main type of injection pump belongs to a newer generation, where electronics begin to dominate everything.
Repair and adjustment of the high pressure fuel pump.
Repair and adjustment of high-pressure fuel equipment is a rather difficult task that requires both theoretical and practical training. Very few motorists are trying to climb into its settings on their own, and even more so to repair it. Most often, diesel fuel pumps are engaged in specialized repair and diagnostic stations, which are provided necessary equipment and qualified personnel.
The only task that you can venture on your own is to adjust the speed idle move(its description can often be found in the car's operating instructions) - I advise you to read the article. As a rule, it implies tightening the accelerator cable until it reaches required parameters. However, even such a simple procedure is not always available to ordinary motorists on engines with electronic control injection. Indeed, here, in addition to the mechanical adjustment itself, it is most often necessary to perform also electronic tuning system, which without special equipment you won't produce.
Well, in conclusion, I would like to note the fact that the injection pump is enough expensive detail engine, the breakdown of which very often hits the car owner quite hard.
The main reasons that lead to breakdowns of the fuel pump can be called poor quality fuel and non-compliance with the rules of diagnostics. So as a tip:
1. try to refuel only at proven gas stations;
2. as soon as the car's mileage requires service - do not delay, look at the diagnostic station.
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Adjustment of the fuel pump ND-21/4 diesel D-144
Adjustment speed limit The T-40 high-pressure fuel pump (see Fig. 12) is carried out using screw 17. When screw 17 is turned out, the speed at which the regulator begins to operate increases, and when screwed in, it decreases.
The maximum frequency of rotation of the diesel crankshaft in idle mode is regulated by changing the stiffness of the spring by increasing or decreasing its working coils. With a decrease in the number of working turns, the idle speed increases, with an increase, it decreases.
The minimum idle speed is automatically adjusted by moving the control lever to the position corresponding to the stable operation of the diesel engine.
Adjustment of the amount of fuel supplied by the pump at starting speed is carried out by turning the eccentric pin 9. When turning it down, the fuel supply by the pump increases, when turning it up, it decreases.
Adjustment of the fuel supply (without opening the pump covers) at nominal speed is carried out by moving the corrector body relative to the cover. When turning out the corrector, the fuel supply increases, when screwing it in, it decreases.
Adjustment of correction of fuel TNVD D-144
The increase in fuel supply required to provide the required margin of diesel torque at a certain crankshaft speed depends on the protrusion of the corrector rod 24 relative to the housing 23 (i.e., on the stroke of the rod), the stiffness of the spring and its preload.
The stroke of the rod is regulated by the number of gaskets under the rod; it should be within 0.38-0.65 mm. The preload of the spring, equal to 3 N (0.3 kgf), is adjusted by the screw 21 of the corrector.
With an increase in the stroke of the corrector rod and a decrease in the tension of the spring, the fuel supply increases and vice versa. You can adjust the corrector on a non-motorized stand with the pump running.
The procedure for adjusting the fuel pump ND-21/4 engine D-144
Work on adjusting the high pressure fuel pump ND-21/4 of the D144 engine of the T-40 tractor should be carried out on the adjustment stand in the following sequence:
Install the pump on the stand bracket;
They check the reliability of fastening the pump to the bracket, the play in the coupling (permissible play is not more than 1 °) and the oil level in the pump crankcase;
Connect the fuel supply system of the stand with the booster pump with fuel lines (the connections of the fuel line elbows with the fittings must be tightened until a reliable seal is obtained, the nut of the fuel supply fitting to the pump is not fully tightened);
The low-pressure system of the D-144 engine of the T40 tractor is pumped with a manual fuel priming pump until a solid jet of fuel free of air bubbles appears from under the fitting for supplying the pump to the pump;
Tighten the nut of the fuel supply fitting to the pump until a reliable seal is obtained;
Create a pressure of 0.15-0.30 MPa (1.5-3.0 kgf/cm2) in the power supply system with a manual fuel pump;
Rotate the stand spindle manually until fuel is supplied through the high pressure fitting;
Connect the high-pressure fuel lines to the pump with injectors;
Fix the control lever in the position of maximum fuel supply;
Turn on stand. Camshaft rotation in reverse side not allowed;
The high pressure system of the D-144 engine of the T-40 tractor is pumped at a spindle speed of 400-600 rpm until a distinct injection of fuel into the glass appears. Otherwise, stop the stand and eliminate the suction of air into the power system;
The fuel supply is regulated (at least 150) at starting speed (50 rpm) by turning the eccentric pin 38 (see Fig. 10);
The stand rotation frequency is set corresponding to the beginning of the regulator action, and with the corrector body turned out, the required fuel supply is adjusted with screw 35.
Check the frequency of rotation of the cam shaft, corresponding to the complete automatic shutdown of the fuel supply through the nozzles, by a smooth increase in the speed of the stand. If necessary, change the number of working turns of the spring 21 of the regulator and repeat the operation;
The nominal speed of the pump shaft ND-21/4 is set, and by moving the body 19 of the corrector with the tightened spring 18, the required fuel supply is regulated. After adjustment, tighten the locknut;
The speed of the pump shaft is set to 650+3° rpm, corresponding to the mode of maximum torque of the diesel engine, and the fuel supply is adjusted by the screw to 64-70 mm3/cycle.
Install and check the correctness of the advance angle of the fuel supply by the diesel pump along the meniscus. It is allowed to crank a diesel engine with a fuel pump with the fuel supply turned on only in the direction of rotation of the diesel crankshaft.
Removal and installation of high pressure fuel pump ND-21/4 of the D-144 engine
Removing the high pressure fuel pump ND-21/4 of the D-144 engine
The fuel pump is removed in the following sequence:
They clean the pump, nozzles, high and low pressure pipes and disassembly points from dirt;
Disconnect the fuel control rod;
Disconnect the high and low pressure pipes and wrap the ends of the low pressure pipes with paper or clean napkins, and cap nuts applied to the diesel engine are screwed onto the fittings of the pump, injectors and high pressure pipes;
Drainer the nozzles are also covered with paper or clean napkins, and a cover is put on the nozzle of the sprayer;
The bolts of the swivel elbows of the fuel line are installed with protective bushings;
Unscrew the bolts securing the pump flange to the cover of the timing gears (or to the crankcase of the pneumatic system compressor) and, moving the pump back, remove it.
After removing the pump, the holes in the cover of the timing gears and the front sheet are closed.
Installation of the fuel pump TNVD ND-21/4 and injectors
The adjusted pump ND-21/4 of the D-144 engine of the T-40 tractor is also installed in a certain order:
Remove the oil filler neck. Insert the fuel pump shaft into the bushing of the drive gear (or into the bushing of the crankshaft of the pneumatic system compressor), align the wide slot on the bushing of the pump shaft with the wide cavity in the splined flange of the drive (or in the bushing of the crankshaft of the pneumatic system compressor) and tighten the bolts;
Wrap the nozzles, install the valve covers. The valve cover of the first cylinder is not installed;
Replace the removed fuel lines. Connect the fuel supply control rod to the regulator lever.
After starting the diesel engine, you should check for leaks in the places where the high-pressure pipes are attached and make sure that the nozzles fit snugly to the seats. The breakthrough of gases between the nozzle and the seat causes the nozzle to overheat and disable the atomizer.
Checking and setting the fuel injection start angle injection pump ND-21/4 engine D144 tractor T-40
Disconnect the high pressure fuel line from the fitting of the first cylinder section and install a momentoscope on this fitting. Turn on the decompressor.
Set the fuel supply control lever to the full supply position and slowly turn the diesel crankshaft until the fuel meniscus rises in the momentoscope tube.
In this case, the pointer fixed on the cover of the timing gears must coincide with the second risk of the T mark on the fan drive drive pulley.
Rice. 16. Fuel pump drive ND-21/4 engine D-144
1 - connecting strip; 2 - flange; 3 - fuel pump drive gear; 4 - washer; 5 - roller nut; 6 - locking plate; 7 - bolt
To set the angle of the start of fuel supply by the pump, unscrew two bolts 7 (Fig. 16) fastening the splined flange and connecting plate.
Remove connecting plate. Turn the crankshaft until the pointer coincides with the corresponding risk on the crankshaft pulley, while both valves of the first cylinder must be closed (end of the compression stroke).
Turn the shaft of the fuel pump ND-21/4 (or the compressor shaft) with a key until fuel appears (without air bubbles) in the momentoscope tube.
After the appearance of a clean jet, part of the fuel is drained from the tube and the fuel pump shaft (or compressor shaft) is slowly turned until the fuel meniscus rises in the momentoscope tube (fuel supply begins).
Holes are found on the slotted flange 2, coinciding with the holes on the gear 3 and bolts 7 are screwed into them, having previously installed the connecting plate 1 and the locking plates 6.
After re-check tighten the bolts and fix their position with the antennae of the locking plate. Remove the momentoscope and attach the fuel line of the first cylinder. Install the valve cover of the first cylinder and the oil filler neck.
Checking the operation of the fuel equipment of the high-pressure fuel pump ND-21/4 of the D-144 engine
The appearance of a smoky exhaust can be caused by an overload of the diesel engine, improper adjustment of the fuel equipment. When the power of a diesel engine without a smoky exhaust drops, the condition is checked fuel filters and in case of contamination, wash the filter element coarse cleaning and replace the fine filter element.
During operation of the diesel engine with interruptions and smoky exhaust and a simultaneous drop in power, the operation of the injectors and the fuel pump is checked.
When operating a diesel engine winter time it is dangerous to get water into the fuel - the water freezes and closes the openings of the filter and the booster pump.
Adjustment and replacement of parts of the fuel pump is necessary only in specially equipped workshops.
Filling the D144 diesel power system
After draining the sludge, washing or replacing the fuel filters, as well as when air enters the power system, “air bags” are formed in it, making it difficult to start and causing interruptions in the operation of the diesel engine.
At the ND 21/4 pump, to remove air, unscrew the bolt securing the swivel elbow of the fuel supply pipeline or the air outlet plug and pump the system with a hand pump.
On a running diesel engine, air removal occurs automatically. During operation, the booster pump constantly maintains excess pressure in the power supply system.
Air, together with fuel, from the horizontal channel of the fuel filter through a calibrated hole and a tube enters the fuel tank. From the tank, the air passes through a filter mounted in the lid to the atmosphere.
If air enters the fuel system again, check if all fuel line connections are tight. If there is confidence in the tightness of the system, it is not pumped.
