Removing the injection pump
To remove the high pressure fuel pump:
- - disconnect the cables for manual control of the engine stop lever and the regulator control lever, the fuel supply control rod, the fuel supply pipelines to the pump, the outlet, drainage pipelines and the pipeline from the fine fuel filter, the oil supply pipe to the pump, the oil drain pipe;
- - unscrew the two bolts of the driven coupling half (to remove the bolts, move them to a convenient position by turning the crankshaft with a crowbar by the holes on the flywheel through the hatch of the clutch housing);
- - disconnect the pipelines supplying fuel to the pin candles, the high pressure pipelines (remove them), the air supply pipe to the auxiliary brake system valve;
- - unscrew the four bolts of the fuel pump;
- - remove the pump.
To install a high pressure fuel pump:
- - turn the crankshaft to the position corresponding to the beginning of fuel injection in the first cylinder (the latch is engaged with the flywheel); in this case, the keyway of the drive coupling half must be:
- - below, for engines mod. 740.11-240 and mod. 740.14-300;
- - in a horizontal position on the left, when viewed from the side of the flywheel for the engine mod. 740.13-260;
Install the pump on the engine, matching:
- - marks on the pump housing and fuel injection advance coupling, for engines mod. 740.11-240 and mod. 740.14-300;
- - alignment mark on the flange of the driven half-coupling with an index on the injection pump housing for the engine mod. 740.13-260;
- - tighten the pump mounting bolts as shown in the figure;
- - without violating the relative position of the marks, tighten the upper bolt of the driven half-coupling of the drive, move the latch into a small groove, turn the crankshaft one turn and tighten the second bolt of the driven half-coupling;
- - install the hatch cover of the clutch housing;
- - connect the high pressure pipelines, the oil supply pipe to the injection pump and the oil outlet pipe, the air supply pipe to the auxiliary brake system valve, the low pressure pipelines, the fuel supply control rod, the manual control cables for the stop lever and the governor control lever.
After installing the high pressure fuel pump, start the engine and use bolt 2 (Fig. High pressure fuel pump regulator cover) to adjust the minimum idle speed, which should be 600±50 min-1.
When repairing the high pressure fuel pump:
- - pump housing with cracks and breaks in the main threads, replace;
- - defects of the plunger sleeve include chipping and chipping of metal at the holes, scuffing, scratches, wear of the working surface, an increase in the diameter of the inlet and cut-off windows, cracks and weakening at the landing sites (chipping, chipping of metal and cracks are irreparable defects).
Measure the wear of the working surface of the plunger bushing with an accuracy of 0.001 mm, the ovality, taper and increase in the hole of the bushing with a micrometer or indicator device for measuring internal surfaces with a division value of up to 0.001 mm and conical gauges;
- plunger defects include chipping of metal and scratches on the working surface, wear of the working surface and cracks.
Distortion of the geometry of the plunger is detected with a minimeter with an accuracy of 0.001 mm when its arrow is set to zero according to the original sample or with a gauge in the form of a conical sleeve;
- check the gap in the plunger pair on a pressure test stand with a falling weight.
Rinse the parts of the pair thoroughly in filtered diesel fuel before testing. Install the plunger pair in the seat of the stand, the plunger in the maximum feed position.
Fill the space above the plunger with filtered diesel fuel.
Install the sealing plate on the end of the sleeve, tightening it with a screw, then release the weight latch. Under its action, fuel will gradually be squeezed out through the gap in the steam - the larger the gap, the faster.
The load on the plunger must correspond to the fuel pressure of 19.1-20.1 MPa (195-205 kgf/cm2).
Full lift the plunger until the moment of cut-off under the action of the load, accompanied by squeezing the fuel through the gap between the bushing and the plunger, must occur in at least 20 s.
Install the plunger pair with the plunger rising time to the cut-off of more than 40 s, moistened with filtered diesel fuel, in a vertical position on the end of the sleeve, after placing a sheet of clean paper.
After a five-minute exposure, when the pair is lifted by the plunger shank, the sleeve should lower from the plunger under the action of its own weight;
- the plunger pusher is installed in the hole of the pump housing with a gap of 0.025-0.075 mm.
The maximum allowable clearance during operation is 0.2 mm. Measure the outer diameter of the plunger pusher with a micrometer or a bracket;
- in the assembly unit, the pusher roller - the roller sleeve - the roller axis, the main defect is the wear of the mating surfaces.
The total gap in the mating is 0.022-0.087 mm, the maximum allowable is 0.3 mm (measure with the indicator head).
If the wear exceeds the specified limit, disassemble the pusher and repair, while measuring separately.
The maximum allowable gap in case of wear of the surfaces in the connection of the roller axis - the roller bushing is 0.12 mm, in the connection of the roller bushing - the pusher roller is 0.18 mm.
Measure the outer surfaces of the parts with a micrometer, the inner ones with an inside meter with an indicator.
- on the surface of the camshaft, metal chipping, scuffing, thread breaks, and traces of corrosion are not allowed. The maximum permissible profile height of the cam is not less than 47.7 mm (the height of the cam profile according to design documentation is 47.95-48.05 mm).
Measure with bracket 47.7; the diameter of the necks for the inner rings of the bearings must be at least 30.0 mm (according to design documentation 30.002-30.011 mm), the tightness along the sealing edge of the cuff must be at least 0.5 mm;
- no cracks, dents, traces of corrosion are allowed on the surface of the discharge valve. Valve wear is manifested in the loss of tightness along the sealing cone, in the jamming of the valve in the seat.
Use a 10x loupe to detect defects.
If there is a loss of tightness, rub the seat and valve together along the cone with GOST 3647-71 paste, if the valve sticks in the seat, wash the parts with gasoline or diesel fuel.
If the jam persists, replace the pair;
- the maximum allowable gap in mating the lever pin of the rails - the groove of the rail is 0.18 mm (according to the design code 0.025-0.077 mm), the maximum allowable gap in mating the axis of the leash of the rotary sleeve - the groove of the fuel pump rail is 0.3 mm (according to the design code 0.117 - 0.183 mm).
Use a bore gauge to measure grooves.
When repairing the speed controller:
- replace the top and back covers of the regulator if there are cracks on them. If the oil strainer in the rear cover of the regulator is clogged, blow it out with compressed air. If the filter is defective, replace it.
The operating oil flow through the filter must be at least 1.6 l/h at a pressure of 98.1-294 kPa (1-3 kgf/cm2);
- to determine the suitability for further operation, inspect and measure the load holder of the regulator assembly with the weights without disassembly, since when pressing out, the parts may be damaged and the pairing of the weights, which are selected with a static moment difference of not more than 196 kPa (2 kgf / see2).
Partial or complete disassembly of the assembly unit should be carried out only if the wear exceeds the allowable limit or the parts are destroyed.
The gap between the lever of the regulator spring and the axis of the lever, pressed into the pump housing, should not exceed 0.3 mm
When repairing the low pressure pump and the pre-fuel pump:
- - replace the low-pressure pump and the pre-start fuel pump if there are cracks in the housing, kinks, mechanical damage, corrosion leading to loss of mobility of mating parts;
- - when disassembling and assembling a low-pressure pump, remember that the piston and pump housing are a precisely matched pair and cannot be dismantled.
The pump is disassembled and repaired only if it does not provide the required characteristics;
- - pay special attention to the condition of the assembly unit rod - low pressure pump bushing, since the amount of fuel flowing into the camshaft cavity depends on the amount of wear in the interface.
The gap in the specified mate must not exceed 0.012 mm. Check the clearance without removing the bushing from the pump housing by determining the time of air pressure drop from 490 kPa (5 kgf/cm2) to 392 kPa (4 kgf/cm2) in a 30 cm battery3.
Scheme of installation for measuring the density of a precision assembly unit is shown in the figure.
Install the pump body 8 in the fixture, fill the accumulator with compressed air to a pressure of at least 539 kPa (5.5 kgf / cm2), hermetically disconnect it from the compressed air line and measure the time during which will drop in the battery from 490 kPa (5 kgf/cm2) to 392 kPa (4 kgf/cm2).
Compare the obtained time with similar density readings of a reference precision pair with a gap in the mating of 0.012 mm.
Replace or repair the pair if it is less than the reference density.
Checking the vapor density can be done in a simpler way: pass filtered diesel fuel through the gap between the stem and the bushing.
The volume of fuel leaking through the gap must not exceed 1 cm3 within 20 minutes.
If the stem-sleeve assembly is being replaced, clean the thread surface and end face in the low-pressure pump housing from adhesive residue.
Install the new stem bushing into the pump housing with an epoxy based adhesive.
To ensure the strength and tightness of the connection, pre-degrease the cleaned contact surfaces of the pump housing and bushing with B-70 gasoline.
After tightening the stem bushing to 9.81 Nm (1 kgcm), check that the stem can move freely in it. If necessary, reduce the tightening torque.
During the test, check the pump flow.
Make the installation for testing according to the scheme: fuel tank - coarse fuel filter - vacuum gauge - fuel priming pump - pressure gauge - measuring tank.
Connect the circuit elements with transparent pipelines with an inner diameter of at least 8 mm.
In order to create a vacuum at the inlet to the pump and counterpressure at the outlet, install valves.
Check with summer diesel fuel at a temperature of 25-30 ° C, in the absence of air in the system, make sure that the fuel jet in transparent pipelines is clean.
The pump must draw fuel from a tank installed 1 m below the pump. Pump flow at a camshaft speed of 1100-1300 min-1, a vacuum at the inlet fitting of 23 kPa (173 mmHg) and back pressure:
- - 80-100 kPa (0.8-1.0 kgf/cm2) must be at least 3 l/min for engines mod. 740.11-240 and mod. 740.13-260;
- - 125 kPa (1.25 kgf/cm2) must be at least 3.5 l/min for engine 740.14-300.
With the outlet cock completely closed and the camshaft speed of 1100-1300 min-1, the pump must create a pressure of at least:
- - 400 kPa (4 kgf/cm2) - for engines mod. 740.11-240 and 740.13-260;
- - 600 kPa (6 kgf/cm2) - for engine 740.14-300.
With the inlet valve completely closed and the specified camshaft speed, the minimum vacuum created by the pump should be:
- - 52 kPa (390 mm Hg) - for engines mod. 740.11-240 and 740.13-260;
- - 70 kPa (525 mmHg) - for engine 740.14-300;
- - check the pre-start fuel pump on a stand that has a diagram: fuel tank - coarse filter - fuel pump. The pump must supply fuel from a tank installed 1 m below the hand pump.
Check the pump for leaks by supplying air under the piston at a pressure of 200-300 kPa (2-3 kgf / cm2) for 5-6 seconds, pre-wetting the cavity with diesel fuel.
Use a tool to remove the automatic fuel injection advance clutch.
First, unscrew the nut 2 (see. Fig. Loosening the nut securing the fuel injection advance clutch) securing the clutch.
To do this, insert a screwdriver 4 into the groove of the nut and, holding the coupling 1 from rotation with the wrench 3, unscrew the nut.
Then, screwing puller 2 into the clutch (Fig. Removing the clutch with a tool), remove the clutch.
To disassemble the coupling:
- remove the screws from the case and drain the oil:
- - clamp the stand 6 (Fig. Dismantling the coupling) of the device into the table vice and install the coupling on it, screw the pin 5 into the stand, install the washer 3 and tighten it with the nut 2;
- - use key 1 to unscrew housing 5 (see Fig. Automatic fuel injection advance clutch);
- - remove the leading coupling half 1 with spacers 12, weights 11, springs 8;
- - press out cuffs 4 and 2.
Given that the weights are selected according to the static moment, save their pairing for later installation.
To assemble the clutch:
- - press the cuff 4 into the hole of the leading coupling half;
- - install the leading half-coupling with a mandrel on the hub of the driven one;
- - install shims 6 and springs 8 in cups 7, cups with springs
- - into the guide holes of the weights, in which they must move freely without jamming.
In an arbitrary position of the coupling parts, the gap between the profile surface and the spacer should be no more than 0.15 mm. When the loads are reduced to the stop by turning the leading half-coupling, one of the gaps should be no more than 0.1 mm, the other should be equal to zero.
Adjust the gaps by selecting spacers:
- - press the cuff 2 into the clutch body flush with the inner end surface;
- - install a rubber sealing ring 14 into the groove of the driven coupling half;
- - screw the housing onto the driven coupling half and tighten to a torque of 314-343 Nm (32-35 kgcm);
- - mint the driven coupling half in three places.
Before installing the housing, make sure that the clearances between the housing and the spring cups are equal with the weights fully pressed together. The gap difference should be no more than 0.2 mm.
After assembly, fill the clutch with engine oil used for the engine.
To disassemble the injector use tool I801.20.000.
Clamp the frame 2 (fig. Dismantling the nozzle) of the fixture in a vice, install the nozzle in the groove of the frame with the spray up.
While screwing in bolt 4, press out the injector atomizer with stop 1, then unscrew the atomizer nut with an open-end wrench. After unscrewing the bolt 4. remove the nozzle from the fixture and disassemble it into parts.
Remember that the body and needle of the atomizer are matched as a pair and cannot be dismantled. The maximum allowable gap between the body and the needle of the atomizer is 0.006 mm.
Do not increase the stroke of the sprayer needle by more than 0.4 mm, the diameter of the nozzle holes of the sprayer should not exceed 0.38 mm.
Unsatisfactory operation of the injectors is caused by a decrease in the pressure of the start of fuel injection, which is explained by the wear of the parts associated with the spring and the shrinkage of the spring, therefore, do not allow the height of the injector spacer to be less than 8.89 mm (according to the design code 8.9-9.0 mm).
If scratches and signs of corrosion are found on the spacer (use a magnifying glass with a tenfold increase), replace the part.
Injector defects include spring breakage, clogged and worn nozzle holes, sticking of the needle and wear of its sealing part (causing leakage and poor atomization of fuel).
If necessary, carefully clean the nozzle holes of the atomizer with a steel wire with a diameter of 0.25 mm.
Remove carbon deposits from the outer surface of the sprayer with a wooden block soaked in engine oil or a brass brush. Do not use sharp hard objects or sandpaper.
Before assembling, wash the body of the atomizer and the needle with gasoline and lubricate with filtered diesel fuel, after which the needle, extended from the body by one third of the length of the guide surface, when the atomizer is tilted at an angle of 45 °, should smoothly (without jamming) fall to the stop under the action of its own masses.
When assembling the nozzle, tighten the atomizer nut by pressing the atomizer in tool I801.20.000.
Part dimensions and allowable wear, mm
Automatic fuel injection advance clutch
According to CD /Permissible
- Coupling weight hole diameter 16.032-16.059 / 16.1
- Load axle diameter 15.982-16.000 / 15.86
- Clearance between axle and load 0.032-0.077 / 0.24
- Space Hole Diameter 16.032-16.059 / 16.1
- Drive pin diameter 15.973-16.000 / 15.9
- Gap between pin and spacer hole 0.032-0.086 / 0.2
High pressure fuel pump mod. 337-40
According to CD /Permissible
- Diameter of the hole for the plunger pusher in the pump housing 32.000-32.025 / 32.1
- Plunger pusher diameter 31.950-31.975 / 31.9
- Gap between body h pump and plunger pusher 0.025-0.075 / 0.2
- Roller bushing inner diameter 11.006-11.024 / 11.04
- Roller axle diameter 10.989-11.000 / 10.93
- Gap between roller axle and bushing 0.006-0.035 / 0.11
- Push roller bore diameter 15.000-15.018 / 15.08
- Roller bush OD 14.956-14.984 / 14.9
- Gap between roller sleeve and roller 0.016-0.052 / 0.18
- Bearing inner diameter 29.989-30.001
- Cam journal diameter 30.002-30.011 / 30
- Clearance between camshaft and bearing 0.000 - 0.001 / 0.003
- Inner diameter of rack lever bushing 7.00-7.03 / 7.1
- Rack arm axle diameter 6.945-6.985 / 6.9
- Clearance between axle and bushing 0.015-0.085 / 0.2
- Rack groove width 5.025-5.065 / 5.1
- Rack lever pin diameter 4.988-5.000 / 4.92
- Gap between pin and groove walls 0.025-0.077 / 0.18
- Rack Groove Width (Rotary Sleeve Drive Shaft Groove) 4.100-4.148 / 4.2
- Diameter of pivot pin 3.965-3.983 / 3.9
- Gap between the axis and the walls of the groove 0.117-0.183 / 0.3
- Weight sleeve inner diameter 7.035-7.065 / 7.1
- Adjuster load axle diameter 6.99-7.00
- Gap between load axle and bushing 0.035-0.075
- Internal diameter of the weight roller 7.023-7.050
- Roller axle diameter 6.99-7.00
- Clearance between axle and roller 0.023-0.060
- Control arm bushing inner diameter 12.000-12.035 / 12.25
- Control arm shaft diameter 11.93-11.98
- Clearance between shaft and sleeve 0.020-0.105 / 0.4
- Thrust foot hole diameter 8.023-8.050 / 8.1
- Heel axle diameter 7.99-8.00 / 7.90
- Clearance between axle and hole 0.023-0.060 / 0.2
- Adjuster spring arm hole diameter 10.013-10.033 / 10.15
- Spring arm axle diameter 9.915-9.965 / 9.85
- Clearance between axle and arm hole 0.048-0.118 / 0.3
- Weight holder bore diameter 15,000-15,035 / 15.2
- Diameter of the sphere of the mass coupling sleeve 14.60-14.53 / 14.4
- Gap between sphere and hole 0.40-0.50 / 0.8
- Load clutch lever bore diameter 10.035-10.085 / 10.1
- Adjuster arm bush OD 10.010-10.025 / 9.9
- Gap between bushing and hole in lever 0.010-0.075 / 0.2
- Adjuster arm bushing inner diameter 7.00-7.023 / 7.1
- Arm axle diameter 6.940-6.965 / 6.9
- Clearance between bushing and lever axle 0.035-0.090 / 0.2
- Right rail slot width 5.100-5.148 / 5.2
- Diameter of weight clutch lever pin 4.992-5.000 / 4.95
- Gap between pin and groove walls 0.100-0.156 / 0.25
- Internal diameter of push rod bushing 6.000-6.025
- Stem diameter 5.997-6.020
- Clearance between stem and sleeve 0.0027-0.0045 / 0.01
- Pump body bore diameter 25.000-25.021 / 25.1
- Pump piston diameter 24.98-24.993 24.92
- Gap between piston and body bore 0.007-0.041 / 0.18
- Diameter of tappet hole in regulator cover 19.000-19.023 / 19.09
- Pushrod diameter 18.915-18.975 / 18.89
- Gap between pusher and cover 0.025-0.108 / 0.2
- Pusher hole diameter 7.000-7.016 / 7.05
- Roller shaft diameter 6.973-6.987 / 6.9
- Clearance between axle and tappet 0.013-0.043 / 0.15
- Push roller inner diameter 7.023-7.050 / 7.12
- Roller axle diameter 6.973-6.987 / 6.84
- Clearance between axle and roller 0.036-0.077 / 0.28
Tightening torques for threaded connections, Nm (kgcm)
- Injector fitting 78.5-98.1 (8-10)
- Nozzle nozzle nut. 58.8-78.5 (6 - 8)
- Nut for injector brackets 31.4-39.2 (3.2-4.0)
- Fuel injection advance clutch nut 98.1-117.7(10-12)
- Injection advance clutch housing. 314-343 (32-35)
- Oil filler screws on injection advance clutch housing 4.9-10.8 (0.5-1.1)
- High pressure fuel line nut 24.5-44.1 (2.5-4.5)
- Bolts for low pressure fuel lines to injectors 19.6-24.5 (2.0-2.5)
- Bolts for low pressure fuel lines to solenoid valve 16.7-22.6(1.7-2.3)
- High pressure fuel pump section fitting 98.1-117.7(10-12)
- Nuts securing the flange of the high pressure fuel pump section 24.5-43.2 (2.5-4.4)
- Nuts for fastening the eccentric of the drive of the low pressure fuel priming pump 44.1-54.0 (4.5-5.5)