1) The document provides instructions for maintenance on a fuel injector, including safety requirements, dismantling and inspecting parts, assembly, and testing. 2) Key steps include isolating fuel systems, checking for leaks and wear, cleaning parts with oil and compressed air, and adjusting the injector opening pressure. 3) Proper maintenance ensures safe and reliable engine operation, supports economic performance, and prevents damage from operational problems.

1. Engine v32/40 Ali Raza
Maintenance on the Injector

2. 1. Safety / Requirements
2. Maintenance on the Injector
3. Injector Task and Functional principle
4. Checking/ Testing of injector
5. Dismantling of the injection valve
6. Checking / Inspection parts of the injector
7. Assembling of the Injection valve
Contents /Maintenance on the Injector

3. Safety/Requirements/ Maint
•Engine stopped.
•Air starting system isolated / depressurized .
•Fuel systems isolated / depressurized / drained.
•NCW System isolated / depressurized / drained.
* LOTO applied on all above mentioned.
*Work permit and PPEs are mandatory

4.  Before opening the fuel valve for overhauling,
1. Ensure that the engine is isolated.
2. Fuel inlet and outlet valves are shut . (*)
3. Fuel valve cooling water line (NCW) is isolated/drained.
Safety/Requirements/Maint
/work

5.  When the fuel valve is removed from the cylinder head
1. Ensure to cover the opening with a big cloth or place tappet cover back to
avoid any tool or parts from falling inside the cylinder.
Safety/Requirements/Maint

6.  The fuel under pressure can enter the skin and the
blood stream and is toxic for humans
1.Use appropriate PPEs.
2.Take care that you stay away from the
spray.
3.The fine mist can catch fire and in
inflammable.
4.Do not smoke or use naked lights
where the fuel injectors are being
tested.
Safety/Requirements/ Maint

7. Fuel injector/ Parts
42 Nozzle body 43 Nozzle needle 44 Hexagon nut 45 Adjusting screw
46 Holder 47 Set screw 48 Thrust piece 49 Compression spring
50 Spring plate 51 Parallel pin 52 Nozzle clamping nut

8. Fuel injector/ Parts
Threaded piece
O-ring seal
Conical sealing face
Fuel injection valve
Sealing ring
Thread

9. 4. The nozzle needle will be lifted from
the seat when the pressure in fuel
chamber ( nozzle body ) exceeds the
pretension of the compression spring.
Injector Task and Functional principle
The nozzle needle and needle body is manufactured in a close-pitch selection
1. So the nozzle needle will be guided smoothly in the nozzle body.
2. Sealing the pressure chamber to the spring space.
3. At the same time one spring is forcing the nozzle needle to the supporting surface
and sealing the pressure chamber to the combustion chamber.

10. Sectional view of injector
Injector Task and Functional principle
5. After the nozzle needle is lifted, the fuel flows via the seat through the small spray
wholes into the combustion chamber.
6. The nozzle needle will be lowered to the seat, when the force of the compression
spring exceeds the pressure force of the fuel chamber in the nozzle body.

11. Maintenance Schedule /Maintenance on the Injector
According to the maintenance schedule an overhaul is necessary:
 Every 2K-3K and 5K-6K running hours.
 By deviation from the operational values.

12.  By deviation from the operational values
Maintenance Schedule /Maintenance on the Injector

13. Purpose of the job /Maintenance on the Injector
Why ?
1) For a safe and reliable operation of the engine / plant.
2) Support economic / environment friendly operation.
3) Prevent from operational problems / damage.
4) To operate the engine according to environmental requirements.

14. Fuel injector removing from the engine/ Work Steps
1. Unscrew and remove hexagon nut after removing Tappet cover .
2. Detach the fuel injection pipe.
3. Undo threaded piece screw it right out and remove it from the cylinder
head.
4. Take off the thrust piece .
01 02 04

15. 5. Screw the extractor into thrust ring and remove it.
6. Screw on the threaded spindle (221.182-2) until it makes contact with
injection valve .
7. Push the extractor sleeve (221.182-1) over the threaded spindle
(221.182-2)in doing so observe the location of the cut-out for stud
.Screw on the spindle nut (221.182-3).
Fuel injector removing from the engine/ Work Steps
05 06 07

16. 8. Extract injection valve by turning the spindle nut until it is loose.
9. Unscrew and remove the spindle nut and take off the extractor
sleeve.
10. Screw lifting eye bolt onto the threaded spindle, fasten the rope with
shackle on the lifting eye bolt, and hook the rope onto the lifting
tackle.
Fuel injector removing from the engine/ Work Steps
0908

17. Injector Removing From the Engine
Unscrew and remove hexagon nut Detach the fuel injection pipe Take off the thrust piece Screw extractor into
thrust ring and remove it.
Screw on the threaded spindle until
it make contact with injection valve
1. Push the extractor
sleeve (221.182-1)
over the threaded
spindle;
2. In doing so, observe
the location of the
cut-out for stud .
3. Screw on the spindle
nut (221.182-3).
Extract injection valve by turning
the spindle nut until it is loose.

18. Fuel injector cleaning
 To operate the engine at least one hour with diesel oil.
Correct cleaning procedure of the nozzle is necessary to ensure proper
atomization of the fuel in the combustion chamber.
Steel brush including rotating steel brush will destroy the nozzle spray holes and a new nozzle
element is required.
 By HFO operation you have to clean the internal parts of the injector prior to
the testing.
Fuel injector cleaned:

19. Fuel injector cleaning
Consequences by using rotating steel brushes:
Example of a nozzle tip cleaned by a rotating steel brush causing edges in the nozzle
bores which destroy the atomization.
Complete and clean combustion is a function of fuel atomization.

20. Fuel injector cleaning
Nozzle condition before cleaning & after cleaning with a nylon sponge.

21. Fuel injector fixed in the nozzle test bed/Testing
14 Air coupling
19 Pressure relief valve
4a Filter pressure controller
4b Air tap
6 Upper bar
7 Bottom bar
5 Nozzle jet collection receptacle
8 Pressure gauge
2 Nozzle holder
18 Oil filler neck
10 High-pressure pipe
20 Oil level indicator

22. Before connecting the air supply make sure that the air cock is closed, the pressure
relief valve is open and the pressure regulator at zero position.
Check oil level
Use only anti corrosion oil
Connect air supply
6 – 8 bar working air
Fuel injector fixed in the nozzle test bed/Testing/ Requirements

23. Screw in threaded
piece and connect
hose
Fixed injector in the
clamping device
Bring the oil collector
pan in position
Fuel injector fixed in the nozzle test bed/Testing

24. Fuel injector fixed in the nozzle test bed /Checking opening pressure
1. Close pressure relief valve
2. Open air cock
3. Slowly increase the pressure on
the pressure regulator
4. Note down the opening pressure
5. Decreases in opening
pressure less than 70bar
continue with checking nozzle
bores. (more then 290)
Continue
1
2
3

25. Fuel injector fixed in the nozzle test bed /Checking opening pressure
Dismantle/clean
6. Decreases in opening pressure more than 70bar dismantle the injection
valve (less then 290)

26. 1. Wash injector in oil and remove carbon residue with
nylon sponge
2. Swing receptacle (5) to the side and insert injector
with injection nozzle downwards into nozzle holder
(2).
3. Fix the injector in the nozzle holder (2) with the lower
bar (7) and upper bar (6).
4. Release hexagon nut (44) and turn back adjusting
screw (45) to release the compression spring (49).
5. Unscrew hexagon head screws (60) on the nozzle
holder (2). Turn nozzle holder (2) with injector
through 180° and screw the hexagon head screws (60)
back in.
6. Release nozzle tensioning nut (52) carefully.
7. Unscrew the nozzle tensioning nut and remove nozzle
body. Ensure that the nozzle needle (43) does not fall
out.
Checking opening pressure/ Dismantling a fuel injector

27. 8. Extract nozzle needle (43) from nozzle body and place it in
oil cleaning.
9. Unscrew hexagon head screws (60) on the nozzle holder
(2). Turn nozzle holder (2) with injector back through 180°
and screw the hexagon head screws (60) back in.
10. Remove injector from nozzle holder (2) in the nozzle test
rig and place on the workbench.
11. Unscrew adjusting screw.
12. If internal parts are not loose, screw eye bolt (001.412) into
the thrust piece (48) and extract thrust piece. If installed,
remove set screw (47), then remove pressure spring and
spring cup (50).
13. Place all parts for cleaning in diesel oil and wash them.
Then blow with compressed air.
Checking opening pressure/ Dismantling a fuel injector

28. The component check includes the following:
1. The nozzle bores
2. The condition of the fitting area
3. The movability of the needle
4. Traces of corrosion on the nozzle tensioning nut and the nozzle body
5. The nozzle specification
Tip!
Pay particular attention to such sources of error that caused unsatisfactory results
when the injection valve was checked
Component check / Dismantling a fuel injector

29. Component check / Cleaning the nozzle bores
For nozzle bore cleaning, clamp a suitable wire into the chuck and run it
through the nozzle bores.

30. Component check / Checking nozzle body
Check to see if the nozzle needle can be easily moved in the nozzle
body, without noticeable resistance
42 Nozzle Body
43 Nozzle needle

31. Component check / Seat surfaces
The seats and fitting areas must neither to be reworked by hand nor by
machine, as the required accuracy cannot be achieved

32. Assembling Fuel Injector/ Nozzle Specification
Important!
Prior to assembly, check whether the
specification of the injection nozzle
1. Number 8545973 IMO 1235B
2. Number of nozzle bores 13Nos
3. Bore diameter 43mm
4. Injection angle 82°

33. Assembling Of fuel injector / Inserting of the inner parts
Insert the inner part from the right hand side to the left in the following
sequence:
1. Spring plate
2. Compression spring
3. Thrust pad
1. Spring plate
2. Compression spring
3. Thrust pad

34. Assembling a fuel injector/ Screw in the setting screw
Screw the setting screw in, do not yet
tension the compression spring.
Verify that the spring plate has been
positioned correctly.

35. Assembling a fuel injector/ Check movement of the needle
1. Dip the nozzle needle into
clean Diesel fuel oil, and
insert it into the nozzle body.
2. Verify it moves easily.
42 Nozzle Body
43 Nozzle needle

36. Assembling Of fuel injector/ Clean contact surface
3. Wipe the sealing face dry using
a paper towel.
4.Slip the nozzle body and nozzle needle
onto the holder, paying attention to the
position of the two parallel pins.

37. Assembling a fuel injector/ Tensioning nut
Screw the nozzle tensioning nut onto the holder, hand-tight, and tighten it
to the specified torque. 700NM
“Optimal paste white T” lubricant. Tensioning Nut 700NM

38. Assembling a fuel injector/ Tightening of the tensioning nut
Screw the hexagon nut loosely onto the setting screw, and tighten
it only after adjusting the injection pressure.

39. Fuel injector fixed in the nozzle test bed /Checking opening pressure
1. Close pressure relief valve
2. Open air cock
3. Slowly increase the pressure on the
pressure regulator
4. Adjust opening pressure to required
by tightening the adjusting screw.

40. Thank you
Any question