DIY repair of mtz fuel pump

Malfunctions of the fuel pump UTN-5 of the MTZ-80, MTZ-82 tractor

During the operation of the D-240 diesel engine of the MTZ-80, MTZ-82 tractors, the following malfunctions of the fuel equipment may appear: the diesel does not start, does not develop normal power, it works unstably, the work is accompanied by a smoke release.

To ensure a clear start of the diesel engine, the crankshaft is given a sufficient rotation speed, and the air in the cylinders at this time is compressed so that, at the time of fuel injection, the temperature is sufficient to ignite it, so that the fuel is supplied to the combustion chamber in a timely manner, in sufficient quantity and finely atomized.

The fuel supply can be disrupted for various reasons, the formation of air plugs in the fuel lines, in the head of the fuel injection pump UTN-5 MTZ-82, MTZ-80, in the filters; severe wear of plunger pairs of pumping elements of the pump, spray nozzles; violation of the regulation of the fuel pump or its incorrect installation on a diesel engine.

The appearance of black or gray smoke from the exhaust pipe of a diesel engine indicates that oil has entered the combustion chamber, incomplete combustion of fuel, misfiring of flashes in the cylinders, incorrect setting of the start of fuel delivery by the fuel pump.

The ingress of oil into the combustion chamber can be explained by the extreme wear of the piston group of the MMZ D-240 engine, an excess of oil in the oil pan. Incomplete combustion can be caused by both an excess portion of fuel entering the cylinder and a lack of air.

It is observed with poor fuel atomization by UTN-5 nozzles, the use of an inappropriate fuel grade, with late fuel injection into the diesel cylinders.

An external sign of deterioration in the operation of the D-240 injectors is a smoke exhaust, interruptions in operation and a decrease in diesel power.

To check the injectors, a diesel engine is set to operate in such a way that interruptions are most clearly audible. Then, alternately loosen the union nuts securing the fuel lines of the injectors to the fittings.

If the crankshaft speed does not change after loosening the nut, then the tested injector is faulty.

If the lift pressure of the injector needle (injection pressure) is less than normal due to a change in spring stiffness or leaks in the liner-plunger interface, then the fuel injection time will increase and the atomization quality will be poor.

When the needle lift pressure is greater than normal or the needle sticks in the lower position, the duration of injection and the amount of fuel decrease, which also affects the starting qualities of the diesel engine.

The D-240 nozzles of the MTZ-82, MTZ-80 tractor fuel pump are removed from the diesel engine and adjusted on the device. The injection pressure and tightness of the injectors can be determined without removing them from the diesel engine.

For this, a device and an autostethoscope are used. The device is connected to the tested injector and a forced fuel supply is created by the handle. The injection pressure is set by rotating the injector screw.

If the pressure is not regulated, this indicates a stuck needle in the gun body. The quality of spraying is judged by the characteristic click heard through the autostethoscope, which indicates a clear fit of the needle into the seat of the atomizer at the moment of the end of the injection.

Difficulty starting a tractor diesel engine can be caused by the presence of water in the fuel, a decrease in the air temperature at the end of compression, which is not enough to ignite the fuel.

A decrease in the temperature of compressed air is usually caused by a decrease in pressure at the end of compression due to air leaks through leaks in the piston (with wear or coking of the piston rings, wear of liners and pistons, valve timing, etc.).

The same phenomena are observed when the air cleaner becomes clogged, when the amount of air entering the cylinders decreases.

With a decrease in the ambient air temperature, the crankshaft speed at start-up decreases, due to thickening of the crankcase oil, air leaks through various leaks grow, the temperature of the end of air compression decreases due to heat transfer to the cold walls of cylinders, pistons and combustion chambers.

Diesel D-240 MMZ can be difficult to start due to violation of the adjustment of the advance angle of the start of fuel supply, wear of the plunger pairs of the high pressure fuel pump.

The amount of fuel supplied to the cylinders and the precise operation of the MTZ-82, MTZ-80 engine injectors are interrelated with the deterioration of the plunger pairs of the UTN-5 injection pump.

The technical condition of the plunger pairs is checked with a device that determines the pressure developed by the plunger pairs of the pump at starting speed. The device is connected to the unions of the pumping sections of the fuel pump. Diesel is scrolled with a starting device.

If the developed pressure is at least 30 MPa, then the plunger pair is in good order. The tightness of the discharge valve is checked by the time the pressure drops from 15 to 10 MPa in at least 10 s.

If the readings of the pressure gauge of the device are below the given parameters, the fuel pump UTN-5 of the MTZ-80, MTZ-82 tractor must be repaired.

The operation of the MMZ D-240 diesel engine without load with the emission of gray smoke from the exhaust pipe, and with an increase in the load - black smoke, indicates a late supply of fuel to the cylinders.

The "hard" operation of the diesel engine is accompanied by sharp knocks, and the emission of black smoke from the exhaust pipe with increasing load indicates an early supply of fuel to the cylinders.

The moment of the beginning of the fuel supply by the sections, by which the angle of the beginning of fuel injection into the cylinders is judged, is one of the important parameters that affect not only the power and economic indicators, but also the starting qualities of the diesel engine.

During long-term operation of the tractor, the moment of fuel supply may change as the plunger pairs wear out, therefore from time to time it is controlled with the KI-4941 device.

The change in the moment of fuel supply during operation is explained by the fact that with worn out plunger pairs of the MTZ-80, MTZ-82 fuel pump, if you slowly turn the diesel crankshaft, part of the fuel, due to the high rigidity of the pressure valve spring, will seep into the gap between the plunger and the sleeve, and the discharge valve will open later than with new plunger pairs.

The rigidity of the technological spring of the device is eight to ten times less than the rigidity of the pressure valve spring, and therefore fuel is supplied with any degree of wear of the plunger pair, due to which the valve opens at the moment of overlap of the supra-plunger space.

For UTN-5 pumps, the fuel supply in idle mode is regulated by changing the number of working turns of the regulator spring.

To reduce the fuel supply and the corresponding decrease in the frequency of complete shutdown of the fuel supply, the number of spring turns is increased, and to increase it, it is reduced.

Check the fuel supply at the maximum torque mode (overload mode), changing it in this mode by adjusting the corrector. To increase the fuel supply, the corrector is screwed in or the spring force is changed.

The corrector is adjusted before installing it in the fuel pump regulator. Its stroke should be 1.3. 1.5 mm. It is installed using spacers. The compression force of the corrector spring is 85.90 for pumps of MMZ D-240 diesel engines.It is measured when the corrector rod is flush with the body.

For diesel engines D-240 of the MTZ-80, MTZ-82 tractor with the UTN-5 pump, the starting fuel supply should be 14.5 cm3 per 100 cycles at a camshaft speed of 150 min1.

Set the regulator control lever to the maximum feed position and the amount of rack displacement by the regulator in the direction of increasing the fuel supply using the power lever bolt. The final operation to adjust the pumps is to set the regulator lever to completely shut off the flow.

The starting frequency of rotation of the camshaft of the pump is set, the lever of the regulator is moved to the stop in the screw "Stop" and the fuel is monitored from the injectors. Feeding should stop. Otherwise, unscrew the screw before stopping the feed.

With a decrease in the hydraulic density of precision parts (the appearance of fuel leaks in their interfaces), the pumping element assembly is replaced and at the same time the state of the discharge valve is monitored.

To replace the pump elements, the tractor fuel pump is partially disassembled. At the UTN-5 injection pump, open the regulator cover, disconnect the intermediate lever rod from the rail, unscrew the fastening bolts and remove the assembled regulator.

Then check the amount of axial movement of the camshaft. Axial movement should be no more than 0.2 mm. At the same time, the axial movement of the weight coupling is checked. Its significant movement leads to spontaneous movement of the rack, which causes unstable operation of the diesel engine.

When replacing the pumping element, the hatch of the MTZ-80, MTZ-82 injection pump housing is removed, the locating pin for fixing its sleeve is removed, and then, using the device, the discharge valve assembly with the seat is removed. To remove the pusher spring, the spring support plate is removed, and the pumping element is removed through the hole in the UTN-5 pump head.

When installing new pumping elements, the slot on the ring gear must coincide with the slot on the sleeve, and the mark on the plunger shank must face the pump housing hatch. When installing the gear rims, the pump rack is installed so that the end face of its driver is at a distance of 24.25 mm from the plane of the pump.

Nozzles of the D-240 engine of the MTZ-80, MTZ-82 tractor

The technical condition of the MTZ-80, MTZ-82 nozzles significantly affects the operation of the D-240 tractor diesel engine; the operation of the diesel engine is observed intermittently, its start-up is difficult, etc.

D-240 diesel engines mainly use multi-hole nozzles with pinless spray nozzles. The main malfunctions of the nozzles: wear or freezing (coking) of the nozzles, insufficient fuel injection pressure, poor-quality spray.

If, when checking on the device, one of the above defects is found, the nozzle is disassembled in order to replace the atomizer body with the needle assembly.

To disassemble the nozzle, it is installed in a device or clamped in a vice and the sprayer nuts and springs are unscrewed. A new atomizer is installed and a control check of the injector performance is carried out.

When selecting a nozzle, the nozzles of the MTZ-82, MTZ-80 tractor carefully examine its marking and design.

Externally, the nozzles are similar to each other, however, in design, they have significant differences in the number of spray holes and their size. Residues of carbon and tarry deposits from the outer surfaces are removed with a brass wire brush and rinsed in gasoline.

The atomizer is replaced if its surface has cracks, chips and breaks of any size, and the needle hangs in the body.

In the absence of new sprayers, the D-240 injector can be restored to its proper working capacity by carrying out simple repairs. When the holes of the sprayer are coked, the needle is removed from it, and the spray holes are cleaned with a magnetized drill or wire.

In case of partial loss of tightness (hanging of the needle or slight appearance of smudges on the sprayer when testing the nozzle), the surfaces of the housing and the sprayer needle are “refreshed”.

For this, the needle is clamped in the drill chuck, and it is installed in the spindle of the lathe, setting the rotational speed to 150.200 min-1.

A thin layer of aluminum oxide paste is applied to the cylindrical surface and joint grinding of the body and the needle is carried out until an even shine is obtained over the entire surface. Next, rub the locking cones and the spray needle.

A thin layer of paste is applied to the cone and the conical surfaces are rubbed until a sealing band is formed at the end of the needle, located at the base of the locking cone. The width of the belt should be 0.5. 0.7 mm.

At the same time, the end surfaces of the nozzle body and the D-240 sprayer are "refreshed". Remove the pins from the nozzle body, apply a layer of paste to the lapping plate and polish the end of the body until an even shine is obtained. After cleaning and lapping work, all parts are washed in gasoline and wiped thoroughly.

After installing and tightening the nut of the spray nozzle D-240, check the ease of movement of the needle. To do this, shake the nozzle.

The spray needle should hit the body. The torque of the gun nut is 0.7. 0.8 Nm, nozzle cap 0.8. 1.0 Nm. The final step is to check the density of the atomizer.

The pressure is set according to the pressure gauge of the device 30. 31 MPa and the time of pressure drop (density) is determined from 28 to 23 MPa. It should be at least 10 s for new nozzles, and 3 s for used ones.

When checking the density, fuel leakage through the nozzle holes is not allowed. The minimum density characterizes the maximum clearance between the nozzle body and the needle in its cylindrical part. The minimum gap diameter in this part of the nozzle is 1.2 µm.

If the density is unsatisfactory, the end surfaces of the nozzle and sprayer bodies of the MTZ-80, 82 tractor are "refreshed". If after that the required density is not reached, the complete spray is replaced. At normal density, the injectors regulate the operating pressure at the start of injection.

After assembling and testing the D-240 injectors, they are checked for throughput. The injectors selected for a set for operation on one diesel engine should not differ in capacity by more than 4% from the average value of the capacity of the entire set of injectors.

To check this parameter, the injectors are installed on a test bench and the flow rate of each nozzle is determined for 1000 cycles at the nominal rotational speed of the camshaft of the UTN-5 fuel pump.

Malfunctions of the fuel pump TNVD UTN-5 engine D-240

During the operation of the D-240 diesel engine of the MTZ-80, MTZ-82 tractors, the following malfunctions of the fuel equipment may appear: the diesel does not start, does not develop normal power, it works unstably, the work is accompanied by a smoke release.

To ensure a clear start of the diesel engine, the crankshaft is given a sufficient rotation speed, and the air in the cylinders at this time is compressed so that, at the time of fuel injection, the temperature is sufficient to ignite it, so that the fuel is supplied to the combustion chamber in a timely manner, in sufficient quantity and finely atomized.

The fuel supply can be disrupted for various reasons, the formation of air plugs in the fuel lines, in the head of the fuel injection pump UTN-5, in the filters; severe wear of plunger pairs of pumping elements of the pump, spray nozzles; violation of the regulation of the fuel pump or its incorrect installation on a diesel engine.

The appearance of black or gray smoke from the exhaust pipe of a diesel engine indicates that oil has entered the combustion chamber, incomplete combustion of fuel, misfiring of flashes in the cylinders, incorrect setting of the start of fuel delivery by the fuel pump.

The ingress of oil into the combustion chamber can be explained by the extreme wear of the piston group of the MMZ D-240 engine, an excess of oil in the oil pan. Incomplete combustion can be caused by both an excess portion of fuel entering the cylinder and a lack of air.

It is observed with poor fuel atomization by UTN-5 nozzles, the use of an inappropriate fuel grade, and late fuel injection into the diesel cylinders.

An external sign of deterioration in the operation of the D-240 injectors is a smoke exhaust, interruptions in operation and a decrease in diesel power. To check the injectors, set the diesel operating mode in which the interruptions are most clearly audible. Then, alternately loosen the union nuts securing the fuel lines of the injectors to the fittings.

If the crankshaft speed does not change after loosening the nut, then the tested injector is faulty. If the lift pressure of the injector needle (injection pressure) is less than normal due to a change in spring stiffness or leaks in the liner-plunger interface, then the fuel injection time will increase and the atomization quality will be poor.

When the needle lift pressure is greater than normal or the needle sticks in the lower position, the duration of injection and the amount of fuel are reduced, which also affects the starting qualities of the diesel engine.

The D-240 fuel pump injectors are removed from the diesel engine and adjusted on the device. The injection pressure and tightness of the injectors can be determined without removing them from the diesel engine. For this, a device and an autostethoscope are used. The device is connected to the tested injector and a forced fuel supply is created by the handle. The injection pressure is set by rotating the injector screw.

If the pressure is not regulated, this indicates a stuck needle in the gun body. The quality of spraying is judged by the characteristic click heard through the autostethoscope, which indicates a clear fit of the needle into the seat of the atomizer at the moment of the end of the injection.

Difficulty starting a diesel engine can be caused by the presence of water in the fuel, a decrease in air temperature at the end of compression, which is not enough to ignite the fuel.

A decrease in the temperature of compressed air is usually caused by a decrease in pressure at the end of compression due to air leaks through leaks in the piston (with wear or coking of the piston rings, wear of liners and pistons, valve timing, etc.). The same phenomena are observed when the air cleaner becomes clogged, when the amount of air entering the cylinders decreases.

With a decrease in the ambient air temperature, the crankshaft speed at start-up decreases, due to thickening of the crankcase oil, air leaks through various leaks grow, the temperature of the end of air compression decreases due to heat transfer to the cold walls of cylinders, pistons and combustion chambers.

Diesel D-240 MMZ can be difficult to start due to violation of the adjustment of the advance angle of the start of fuel supply, wear of the plunger pairs of the high-pressure fuel pump.

The amount of fuel supplied to the cylinders and the precise operation of the MTZ-80, MTZ-82 engine injectors are interrelated with the deterioration of the plunger pairs of the UTN-5 injection pump.

The technical condition of the plunger pairs is checked with a device that determines the pressure developed by the plunger pairs of the pump at starting speed. The device is connected to the unions of the pumping sections of the fuel pump. Diesel is scrolled with a starting device.

If the developed pressure is at least 30 MPa, then the plunger pair is in good order. The tightness of the discharge valve is checked by the time the pressure drops from 15 to 10 MPa in at least 10 s.If the readings of the pressure gauge of the device are below the given parameters, the fuel pump of the injection pump UTN-5 must be repaired.

The operation of the MMZ D-240 diesel engine without load with the emission of gray smoke from the exhaust pipe, and with an increase in the load - black smoke, indicates a late supply of fuel to the cylinders. The "hard" operation of the diesel engine is accompanied by sharp knocks, and the emission of black smoke from the exhaust pipe with increasing load indicates an early supply of fuel to the cylinders.

The moment of the beginning of the fuel supply by the sections, by which the angle of the beginning of fuel injection into the cylinders is judged, is one of the important parameters that affect not only the power and economic indicators, but also the starting qualities of the diesel engine.

During long-term operation of the MTZ-80, MTZ-82 tractor, the moment of fuel supply may change as the plunger pairs wear out, therefore from time to time it is controlled with the KI-4941 device.

The change in the moment of fuel supply during operation is explained by the fact that with worn-out plunger pairs of the fuel pump, if you slowly turn the crankshaft, part of the fuel, due to the high stiffness of the pressure valve spring, will leak into the gap between the plunger and the liner, and the pressure valve will open later than with new plunger pairs.

The rigidity of the technological spring of the device is eight to ten times less than the rigidity of the pressure valve spring, and therefore fuel is supplied with any degree of wear of the plunger pair, due to which the valve opens at the moment the supra-plunger space closes. For UTN-5 pumps, the fuel supply in idle mode is regulated by changing the number of working turns of the regulator spring.

To reduce the fuel supply and the corresponding decrease in the frequency of complete shutdown of the fuel supply, the number of spring turns is increased, and to increase it, it is reduced.

Check the fuel supply at the maximum torque mode (overload mode), changing it in this mode by adjusting the corrector. To increase the fuel supply, the corrector is screwed in or the spring force is changed.

The corrector is adjusted before installing it in the regulator of the UTN-5 fuel pump. Its stroke should be 1.3. 1.5 mm. It is installed using spacers. The compression force of the corrector spring is 85. 90 for pumps of MMZ D-240 diesel engines. It is measured when the corrector rod is flush with the body.

The starting fuel supply should be 14.5 cm3 per 100 cycles at a camshaft speed of 150 min1. Set the regulator control lever to the maximum feed position and the amount of rack displacement by the regulator in the direction of increasing the fuel supply using the power lever bolt. The final operation to adjust the pumps is to set the regulator lever to completely shut off the flow.

The starting frequency of rotation of the camshaft of the pump is set, the lever of the regulator is moved to the stop in the screw "Stop" and the fuel is monitored from the injectors. Feeding should stop.

Otherwise, unscrew the screw before stopping the feed. With a decrease in the hydraulic density of precision parts (the appearance of fuel leaks in their interfaces), the pumping element assembly is replaced and at the same time the state of the discharge valve is monitored.

To replace the pumping elements, the fuel pump of the MTZ-80, MTZ-82 tractor is partially disassembled. At the UTN-5 injection pump, open the regulator cover, disconnect the intermediate lever rod from the rail, unscrew the fastening bolts and remove the assembled regulator. Then check the amount of axial movement of the camshaft.

Axial movement should be no more than 0.2 mm. At the same time, the axial movement of the weight coupling is checked. Its significant movement leads to spontaneous movement of the rack, which causes unstable operation of the diesel engine.

When replacing the pumping element, the hatch of the D-240 fuel injection pump housing is removed, the dowel pin fixing its sleeve is removed, and then, using the device, the discharge valve assembly with a seat is removed. To remove the pusher spring, the spring support plate is removed, and the pumping element is removed through the hole in the UTN-5 pump head.

When installing new pumping elements, the slot on the ring gear must match the slot on the sleeve, and the mark on the plunger shank must face the pump housing hatch. When installing the gear rims, the pump rack is installed so that the end face of its driver is at a distance of 24.25 mm from the plane of the pump.

Diesel injectors D-240

The technical condition of the MTZ-80, MTZ-82 nozzles significantly affects the operation of the D-240 tractor diesel engine; the operation of the diesel engine is observed intermittently, its start-up is difficult, etc. In general, nozzles with pinless spray nozzles, multi-hole, are used. The main malfunctions of the nozzles: wear or freezing (coking) of the nozzles, insufficient fuel injection pressure, poor-quality spray.

If, when checking on the device, one of the above defects is found, the nozzle is disassembled in order to replace the atomizer body with the needle assembly. To disassemble the nozzle, it is installed in a device or clamped in a vice and the sprayer nuts and springs are unscrewed. A new atomizer is installed and a control check of the injector performance is carried out.

When selecting a spray nozzle, carefully examine its marking and design. Externally, the nozzles are similar to each other, however, in design, they have significant differences in the number of spray holes and their size. Residues of carbon and tarry deposits from the outer surfaces are removed with a brass wire brush and rinsed in gasoline.

The atomizer is replaced if its surface has cracks, chips and breaks of any size, and the needle hangs in the body. In the absence of new sprayers, the D-240 injector can be restored to its proper working capacity by carrying out simple repairs.

When the holes of the sprayer are coked, the needle is removed from it, and the spray holes are cleaned with a magnetized drill or wire. In case of partial loss of tightness (hanging of the needle or insignificant appearance of smudges on the sprayer when testing the nozzle), the surfaces of the housing and the sprayer needle are “refreshed”.

For this, the needle is clamped in the drill chuck, and it is installed in the spindle of the lathe, setting the rotational speed to 150.200 min-1. A thin layer of aluminum oxide paste is applied to the cylindrical surface and joint grinding of the body and the needle is carried out until an even shine is obtained over the entire surface.

Next, rub the locking cones and the spray needle. A thin layer of paste is applied to the cone and the conical surfaces are rubbed until a sealing band is formed at the end of the needle, located at the base of the locking cone. The width of the belt should be 0.5. 0.7 mm.

At the same time, the end surfaces of the nozzle body and the sprayer are "refreshed". Remove the pins from the nozzle body, apply a layer of paste to the lapping plate and polish the end of the body until an even shine is obtained. After cleaning and lapping work, all parts are washed in gasoline and wiped thoroughly.

After installing and tightening the nozzle nut of the D-240 internal combustion engine nozzle, check the ease of the needle stroke. To do this, shake the nozzle. The spray needle should hit the body. The torque of the gun nut is 0.7. 0.8 Nm, nozzle cap 0.8. 1.0 Nm. The final step is to check the density of the atomizer.

The pressure is set according to the pressure gauge of the device 30. 31 MPa and the time of pressure drop (density) is determined from 28 to 23 MPa. It should be at least 10 s for new nozzles, and 3 s for used ones.

When checking the density, fuel leakage through the nozzle holes is not allowed.The minimum density characterizes the maximum clearance between the nozzle body and the needle in its cylindrical part. The minimum gap diameter in this part of the nozzle is 1.2 µm.

If the density is unsatisfactory, the end surfaces of the nozzle and sprayer bodies of the MTZ-80, MTZ-82 tractor are refreshed. If, after that, the required density is not reached, the nebulizer assembly is replaced. At normal density, the injectors regulate the operating pressure at the start of injection.

After assembling and testing the D-240 injectors, they are checked for throughput. The injectors selected for a set for operation on one diesel engine should not differ in capacity by more than 4% from the average value of the capacity of the entire set of injectors.

To check this parameter, the injectors are installed on a test bench and the flow rate of each nozzle is determined for 1000 cycles at the nominal rotational speed of the camshaft of the UTN-5 fuel pump.

Belarus tractors MTZ-80, MTZ-82, MTZ-82.1, MTZ-1221, 1523, MTZ-892, YuMZ, T-40. Agricultural machinery: plows, cultivators, walk-behind tractors, mowers, seeders

SPARE PARTS FOR TRACTORS

ADJUSTMENT OF MTZ TRACTORS ___________________

DIESEL ENGINE PARTS ___________________

SPARE PARTS CATALOGS MTZ ___________________

TECHNICAL CHARACTERISTICS OF TRACTORS ___________________

SPECIAL EQUIPMENT BASED ON MTZ AND ATTACHED EQUIPMENT ___________________

AGRICULTURAL MACHINERY AND EQUIPMENT ___________________

During the operation of the D-240/243 diesel engine of the MTZ-80, MTZ-82 tractors, the following signs of malfunctions of the fuel pump of the high-pressure fuel pump may appear: the diesel does not start up, does not develop normal power, operates unstably or works with a smoky exhaust.

These signs are largely due to a violation of the fuel supply. The reasons for the disruption of the fuel supply of diesel engines D-240/243 of the MTZ-80, MTZ-82 tractors can be: the formation of air plugs in the fuel lines, the head of the fuel pump of the injection pump, filters; heavy wear
plunger pairs of the fuel pump, injector nozzles; violation of the regulation of the fuel pump or its incorrect installation on a diesel engine.

The appearance of black or gray smoke from the exhaust pipe of a diesel engine indicates incomplete combustion of fuel, missing flashes in the cylinders, incorrect setting of the start of the fuel injection pump.

Incomplete combustion can be caused by both excess fuel entering the cylinder and lack of air. It is also observed in case of poor sawing of fuel by nozzles, the use of fuel of an inappropriate grade, and late injection of fuel into the diesel cylinders.

Outward signs of deterioration of the injectors are smoke exhaust, interruptions in operation and a decrease in diesel power.

To check the nozzles of the D-240/243 engine of the MTZ-80, MTZ-82 tractors, set the diesel operating mode in which interruptions are most clearly audible.

Then, alternately loosen the union nuts securing the fuel lines of the injectors to the fittings of the high-pressure fuel pump of the high-pressure fuel pump. If the crankshaft speed does not change after loosening the nut, then the tested injector is faulty.

If the lifting pressure of the D-240/243 nozzle needle of the MTZ-80, MTZ-82 tractor (injection pressure) is less than normal as a result of a change in the spring stiffness or the appearance of leaks in the sleeve-plunger interface, then the fuel injection duration will increase, and the quality
spraying will decrease.

When the needle lift pressure is greater than normal or the needle sticks in the lower position, the duration of injection and the amount of fuel entering the cylinder will decrease, which also affects the starting performance of the diesel engine.

The nozzles are removed from the D-240/243 diesel engine of the MTZ-80, MTZ-82 tractors and adjusted on the KI-562, KI-3333 or KI-15706 device to an injection pressure of 17.8-18.5 MPa.

The injection pressure and tightness of the injectors can be determined without removing them from the diesel engine. To do this, use the KI-16301A device and an autostethoscope.

The device is connected to the tested injector, having previously disconnected the high-pressure fuel line, and a forced fuel supply is created with the handle.

The injection pressure is set by rotating the D-240/243 nozzle screw of the MTZ-80, MTZ-82 tractor. If the pressure is not regulated, this indicates a stuck needle in the gun body. The quality of spraying is judged by the characteristic click heard with an autostethoscope.

The presence of such a click indicates a clear fit of the needle in the nozzle seat at the moment of the end of the injection.

The release of coolant from the radiator steam pipe may indicate a violation of the tightness of the nozzle cup seals, breakdown and cracks in the cylinder head of the D-240/243 diesel of the MTZ-80, MTZ-82 tractors.

The nozzle glass is removed from the block head, having previously cut the M24X2.0 thread on the inner surface of the glass and using a device consisting of a bracket with a power screw and a nut. The device is installed on the nozzle pins.

Difficult starting of the D-240/243 diesel engine of the MTZ-80, MTZ-82 tractors can be caused by the presence of water in the fuel, a low temperature of the mixture at the end of the compression stroke, which is insufficient to ignite the fuel.

Other reasons for the difficult start of the diesel engine may be violations of the adjustment of the advance angle of the start of fuel supply and wear of the plunger pairs of the high-pressure fuel pump.

The amount of fuel supplied to the cylinders and the precise operation of the injectors are due to the technical condition of the plunger pairs of the injection pump D-240/243 of the MTZ-80, MTZ-82 tractor.

To check the technical condition of the plunger pairs, use the KI-16301A device (Fig. 1).

The device is connected to the unions of the pumping sections of the high-pressure fuel pump of the high-pressure fuel pump D-240/243 of the MTZ-80, MTZ-82 tractor, having previously disconnected the high pressure fuel lines.

If, when the crankshaft of the diesel engine is cranked by the starting device, the developed pressure is at least 30 MPa, then the plunger pair is serviceable.

During repairs, the tightness of the discharge valve is checked by the time the pressure drops from 15 to 10 MPa; the fall time must be at least 10 s. If the pressure gauge readings are below the given values, the high pressure fuel pump is removed from the D-240/243 diesel engine (Fig. 2, 3) and
replace.

Rice. 1. Checking the technical condition of the plunger pairs and injection valves of the high-pressure fuel pump D-240/243 of the MTZ-80, MTZ-82 tractor

1 - device KI-16301 A; 2 - fuel pump

Rice. 2. Removal of the high pressure fuel pump D-240/243 of the MTZ-80, MTZ-82 tractor

1 - fuel pump; 2 - compressor; 3, 5 - fuel lines; 4 - pump control rod

Rice. 3. Unscrewing the fastening bolts of the fuel pump D-240/243 of the MTZ-80, MTZ-82 tractor (front view)

1 - fuel pump drive gear cover

The appearance of gray smoke from the exhaust pipe during no-load operation of the diesel engine and the appearance of black smoke with an increase in the load indicate late fuel supply to the cylinders.

The hard work of the D-240/243 diesel engine of the MTZ-80, MTZ-82 tractors, accompanied by sharp knocks, and the appearance of black smoke from the exhaust pipe with an increase in load indicate an early fuel supply to the cylinders.

The moment of the beginning of the fuel supply by the sections, by which the angle of the beginning of fuel injection into the cylinders is judged, is one of the important parameters that affect not only the power and economic indicators, but also the starting qualities of the diesel engine.

After the repair, the injection pump is installed on the D-240/243 diesel of the MTZ-80, MTZ-82 tractor, the angle of the start of fuel injection is adjusted. To do this, unscrew the adjusting bolt-pin from the threaded hole of the rear sheet of the diesel engine and insert it with the uncut part into the same hole until it stops in the flywheel.

Turn the crankshaft by the fan drive pulley mounting bolt (Fig. 4) until the adjusting stud bolt coincides with the hole in the flywheel; while the valves of the first cylinder must be closed.This position of the crankshaft corresponds to the advance angle of the start of fuel supply equal to 26 ° to TDC.

A device, a momentoscope KI-4941, is installed on the fitting of the first section of the fuel pump D-240/243 of the MTZ-80, MTZ-82 tractor.

Open the cover of the gear wheel of the fuel pump drive, bend the tendrils of the lock plate and unscrew the bolts securing the drive flange (the camshaft of the pump to the gear (Fig. 5).

The power system is pumped with a hand pump until the fuel leaves the filter drain tube without air bubbles. Set the fuel supply lever to the full supply position and turn the fuel pump shaft clockwise several times until the momentoscope tube is filled with fuel.

Rice. 4. Rotation of the crankshaft of the D-240/243 diesel tractor MTZ-80, MTZ-82

1 - diesel back sheet; 2 - bolt-stud

Fig. 5. Unscrewing the bolts in the fastening of the flange of the camshaft drive of the pump D-240/243 of the MTZ-80, MTZ-82 tractor

1 - splined flange; 2 - lock plate

Rice. 6. Adjustment of the axial clearance of the gear wheel of the fuel pump drive of the fuel pump D-240/243 of the MTZ-80, MTZ-82 tractor

1 - adjusting bolt; 2 - lock nut

Slightly shake the tube to remove part of the fuel from it and carefully turn the fuel pump shaft clockwise until the fuel level (meniscus) in the glass tube of the momentoscope starts to rise.

Holding the bolt of the injection pump shaft D-240/243 of the MTZ-80, MTZ-82 tractor from spontaneous rotation with a key, they find holes on the splined flange that coincide with the holes of the gear, screw in the fastening bolts and fix them with a locking plate.

After installing the cover of the pump drive gear, adjust the axial clearance of the fuel pump drive gear with bolt 1 (Fig. 6). Having released the lock nut, screw in the adjusting bolt until it stops, then unscrew it half a turn and end with a nut.

The purpose of the injection pump is to move the diesel fuel from the tank to the engine cylinders. The main components of the power system are two tanks for diesel fuel, filters for coarse and fine cleaning of fuel, a high-pressure fuel pump - high pressure fuel pump. The power supply system of "Belarus" equipment is relatively elementary, it has a classic look and principle of operation. Having studied it well, having dealt with the device at a theoretical level, you can safely carry out repairs yourself. The fuel system of this tractor contains about seventy parts, which is not enough for such equipment.

The tractor pump for MTZ 80 is called UTN-5. It is made of durable aluminum alloy. And they are released in different variations of mounting, there is a left and right version. It depends on the design and properties of the fastener. Along the entire length of the body, it is divided into two cavities. This is due to the baffle. At the bottom there is a shaft with a pump drive, and at the top there are the integral sections of this pump.

We will consider the detailed design of the injection pump of the D-240 motor further. A fuel pump with a regulating mechanism has the following elements: a pressure nipple, a delivery valve, a valve seat, a plunger and a corresponding sleeve, a swivel sleeve, a crown with teeth, a rack rod, a regulator cover, a corrector body, a corrector stem, a regulator body, a heel, a weight axis , heels and levers, coupling, regulator weights, weights hub, shock absorber cracker, bearing cup, oil deflector, shaft with cam, plug, pump mounting flange, mounting plate, splined sleeve, mounting flange, roller pusher, bottom spring plate, rack with gear, fuel outlet channels, bypass valve body, diesel fuel supply hole, ball valve, fuel channels, cut-off hole, pin, plunger sleeve inlet, manhole cover.Like any pump, the injection pump in its design has washers, clamps, main and auxiliary levers, bolts for various purposes, ball bearings, springs, plugs, nuts, gaskets, pipes for transferring fuel, various screws for tightening and adjusting. There is no pump in nature without a housing and a hole for oil, there are no pumps without an eccentric for pumping fuel.

Diagram of a fuel pump with a regulator

The feeding system of a diesel engine includes: an air cleaner, a muffler, an air filter, an electric torch heater with a fuel tank, an intake manifold, various pipes - drainage and high pressure, a throat for filling fuel, fuel tanks, a drain cock, filters for fine and coarse diesel fuel cleaning, fuel pump regulator, booster pump, fuel pump, injectors, exhaust manifold, filtering devices for various purposes.

At the highest point of UTN-5 there are longitudinal channels connecting it with a fine filter and with a pump pumping system, in which a through-flow valve is built.

The booster pump is attached to the main pump body. A fuel line is connected to the fittings, through which fuel is supplied under high pressure to the injectors. The pump is driven by the crankshaft gear. If the pump has already been repaired, then after the next assembly and disassembly it is necessary to carefully check the angle of the gear connections. Otherwise, with an erroneous inclination, there will be interruptions in performance. The degree of inclination must be strictly 22 ° 30 ″. It is better to check it by contacting an experienced minder.

Before starting, you need to make sure that the closing cone fits snugly and that the pressure of the pump section is correct. We rotate the crankshaft and move the regulator until the arrow on the pressure gauge shows 15 MPa. The engine is then turned off, the fuel supply is stopped with the control lever. If the pressure on the pressure gauge drops within ten seconds, the valve is good.

To adjust the exact angle of the moment of fuel intake, the adjusting bolt must be turned in different directions. One turn reduces or increases the crankshaft speed by about 40 revolutions. Unscrewing the bolt - the pump power decreases, tightening - increases.

By a logical method, it can be calculated that by increasing the supply of the amount of fuel to the combustion chamber, the torque also becomes larger. This increases the engine power and speed.

Changing the engine oil in the UTN-5 device is needed only after dismantling and repair work. This should not be done during normal operation. Engine oil requires only 150-200 milliliters, filling is carried out through the crankcase of the injection pump.