61 Bosch Cri Repair Instructions En

MAKTEST, INC.

Service Manual Bosch CRI Types 1.0, 2.1, 2.2 01.09.2009

Disclaimer: The information presented herein is for guidance o nly. Different applications may have different service procedures to follow. Consult to Maktest i n case of confusion.

Contents Description of Components.............................................................. ................................................................................................................................. ................................................................... 1 Explanation of Name Plate on the t he Injector ..................................................................................................... ..................................................................................................... 1 Identification of CRI types and their Differences ............................................................................................ ............................................................................................ 2 Differences in Nozzle Seat ........................................................................................................................... ........................................................................................................................... 2 Piston Type Spacer .................................................................................................................................. .................................................................................................................................. 2 Piston Spacer in a Guide ................................................................... .......................................................................................................................... ....................................................... 2 Differences in Nozzle End Surface ................................................................... ............................................................................................................... ............................................ 3 Solid Nozzle End-Machined Surface .................................................................................. ........................................................................................................ ...................... 3 Nozzle Seat with Maltese Cross Machined Surface................................................................................. 3 Nozzle Seat with Butterfly Shape Machined Surface .............................................................................. .............................................................................. 3 Differences in Valve Va lve Mechanism Assemblies .............................................................................................. .............................................................................................. 4 CRI 1 type Valve Mechanism .................................................................................. ................................................................................................................... ................................. 4 CRI 2.0 and CRI 2.2 type Valve Mechanism ..................................................................................... ............................................................................................. ........ 5 CRI 2.1 type Valve Mechanism ............................................................................... ................................................................................................................ ................................. 5 Disassembling Nozzle and Checking for Repair .................................................................. ................................................................................................... ................................. 7 Piston Type Spacer ...................................................................................................................................... ...................................................................................................................................... 8 Spacer in a Guide Type ............................................................................................... ................................................................................................................................ ................................. 8 Checking For Repair ........................................................... .............................................................................................................................. .............................................................................. ........... 9 Dissembling the Solenoid and the Valve Group ................................................................................................ ................................................................................................ 10 Dissembling the Solenoid and the Valve Group CRI 2.1 Type (BMW applications) .......................................... 14 Dissembling the High Pressure Inlet Nipple .................................................................................................. .................................................................................................. 16 Checking Components for Repair ............................................................ .................................................................................................................. ...................................................... 16 Assembling CRI Injectors ................................................................................................................................... ................................................................................................................................... 21 Assembling the Valve Seal .............................................................................................. ............................................................................................................................. ............................... 21 Assembling the Control Valve ....................................................................................................................... ....................................................................................................................... 24 Assembling Valve Group of CRI 1.0, 2.0 and 2.2 2. 2 ........................................................................................... ........................................................................................... 25 Daimler – Daimler – Chrysler Chrysler Engine Applications – Applications – Suspension Suspension Ring Assembly .......................................................... .......................................................... 27 Measuring and Setting the Magnet Plate Lift...................................................... Lift................................................................................................ .......................................... 27 Measuring and Setting the Distance between Solenoid and Magnet Plate .............................................. 30 Assembling the Solenoid Group .................................................................................................................... .................................................................................................................... 33 Assembling the CRI 2.2 type Solenoid and Valve Group (BMW Applications) .............................................. 34

Contents Description of Components.............................................................. ................................................................................................................................. ................................................................... 1 Explanation of Name Plate on the t he Injector ..................................................................................................... ..................................................................................................... 1 Identification of CRI types and their Differences ............................................................................................ ............................................................................................ 2 Differences in Nozzle Seat ........................................................................................................................... ........................................................................................................................... 2 Piston Type Spacer .................................................................................................................................. .................................................................................................................................. 2 Piston Spacer in a Guide ................................................................... .......................................................................................................................... ....................................................... 2 Differences in Nozzle End Surface ................................................................... ............................................................................................................... ............................................ 3 Solid Nozzle End-Machined Surface .................................................................................. ........................................................................................................ ...................... 3 Nozzle Seat with Maltese Cross Machined Surface................................................................................. 3 Nozzle Seat with Butterfly Shape Machined Surface .............................................................................. .............................................................................. 3 Differences in Valve Va lve Mechanism Assemblies .............................................................................................. .............................................................................................. 4 CRI 1 type Valve Mechanism .................................................................................. ................................................................................................................... ................................. 4 CRI 2.0 and CRI 2.2 type Valve Mechanism ..................................................................................... ............................................................................................. ........ 5 CRI 2.1 type Valve Mechanism ............................................................................... ................................................................................................................ ................................. 5 Disassembling Nozzle and Checking for Repair .................................................................. ................................................................................................... ................................. 7 Piston Type Spacer ...................................................................................................................................... ...................................................................................................................................... 8 Spacer in a Guide Type ............................................................................................... ................................................................................................................................ ................................. 8 Checking For Repair ........................................................... .............................................................................................................................. .............................................................................. ........... 9 Dissembling the Solenoid and the Valve Group ................................................................................................ ................................................................................................ 10 Dissembling the Solenoid and the Valve Group CRI 2.1 Type (BMW applications) .......................................... 14 Dissembling the High Pressure Inlet Nipple .................................................................................................. .................................................................................................. 16 Checking Components for Repair ............................................................ .................................................................................................................. ...................................................... 16 Assembling CRI Injectors ................................................................................................................................... ................................................................................................................................... 21 Assembling the Valve Seal .............................................................................................. ............................................................................................................................. ............................... 21 Assembling the Control Valve ....................................................................................................................... ....................................................................................................................... 24 Assembling Valve Group of CRI 1.0, 2.0 and 2.2 2. 2 ........................................................................................... ........................................................................................... 25 Daimler – Daimler – Chrysler Chrysler Engine Applications – Applications – Suspension Suspension Ring Assembly .......................................................... .......................................................... 27 Measuring and Setting the Magnet Plate Lift...................................................... Lift................................................................................................ .......................................... 27 Measuring and Setting the Distance between Solenoid and Magnet Plate .............................................. 30 Assembling the Solenoid Group .................................................................................................................... .................................................................................................................... 33 Assembling the CRI 2.2 type Solenoid and Valve Group (BMW Applications) .............................................. 34

Assembling the Nozzle....................................................... Nozzle.......................................................................................................................... ............................................................................ ......... 38 38 Piston Type Spacer .................................................................................................................................... .................................................................................................................................... 38 Measuring and Setting the Nozzle Lift of Injectors with Piston Type Spacers ...................................... 38 Tightening Torque Values for Injectors with Flat End ........................................................................... ........................................................................... 40 Tightening Torque Values for Injectors with Maltese Cross End .......................................................... 41 Tightening Torque Values for Injectors with Butterfly End .......................................................... ................................................................... ......... 41 Guided Shim Type Spacer ................................................................................ .......................................................................................................................... .......................................... 42 Measuring and Setting the Nozzle Lift................................................................................................... 42 Tightening Torque Values for Injectors with Flat End ........................................................................... ........................................................................... 45 Tightening Torque Values for Injectors with Maltese Cross End .......................................................... 46 Tightening Torque Values for Injectors with Butterfly End .......................................................... ................................................................... ......... 46 Testing the Injectors and Interpreting I nterpreting the Results ............................................................. ............................................................................................ ............................... 47 Fine Tuning the Delivery of Common Rail Injector ............................................................. ............................................................................................ ............................... 49 Which part has what affect on the deliveries? ............................................................................................. 49 Ball Lift ............................................................................................................. ....................................................................................................................................................... .......................................... 49 Distance between the Solenoid and the Magnet Plate P late ......................................................... ............................................................................. .................... 49 Thickness of the Solenoid Shim ........................................................... ................................................................................................................. ...................................................... 49 Nozzle Lift L ift ............................................................................................................................................ .................................................................................................................................................. ...... 50 Thickness of the Nozzle Spring Shim ......................................................................................................... ......................................................................................................... 50

Bosch CRI Repair Instructions

Description of Components Explanation of Name Plate on the Injector See below figureHata! figure Hata! Başvuru kaynağı bulunamadı.; bulunamadı.; 1. Serial Number 2. Bosch Order Code 3. Classification

1


Identification of CRI types and their Differences Differences in Nozzle Seat Piston Type Spacer

Piston Type Spacer (2) is actually located between nozzle needle and Control Valve Piston.

Piston Spacer in a Guide

Spacer is placed in a guide (2) and spacer is much smaller that piston type spacer.

2


Differences in Nozzle End Surface Solid Nozzle End-Machined Surface

This type of nozzle body is used on CRI 1 type Bosch injectors with piston type spacers.

Nozzle Seat with Maltese Cross Machined Surface

Usually guided spacer nozzle assembly injectors have this Maltese cross machined surface on their no zzle seat surface.

Nozzle Seat with Butterfly Shape Machined Surface

Injectors with both piston type spacers and guided spacers of CRI 2 type may have Butterfly Shape Machined Surface on their nozzle seat surface.

3


Differences in Valve Mechanism Assemblies CRI 1 type Valve Mechanism

1 2 3

CRI 1 type of Valve Mechanism is very wide spread and first generation valve mechanism. The lock piece (1) must be removed in order to disassemble whole valve mechanism. Connection Plate (2) can be removed only after removing the lock piece, and Control Valve Fixing Nut (3) should be removed using a speci al hexagonal tool.

CRI 1 type mechanism has a variant for Daimler Crysler Engines. One type o f the Valve Mechanism is modified to have a suspension (1) on the Control Plate Assembly to avoid uncontrolled “vibrations” during operation at higher speeds.

4


CRI 2.0 and CRI 2.2 type Valve Mechanism

CRI 2.0 and CRI 2.2 is very similar to CRI 1 type valve mechanism, with one exception that there is a protective cover (1) on top end of the Push Rod. This cover actually covers the lock piece and avoids and damage to push rod and lock piece. In order to disassemble the valve mechanism, the protective cover (3) must be removed and then lock piece should be removed to remove the connection plate. After removing Control Valve Fixing Nut (3), the push rod, ball housing and ball can be removed.

CRI 2.1 type Valve Mechanism

This different design Valve Mechanism does not have any lock piece because the connection plate and push rod is combined into one single push piece (1) and once the solenoid is removed, it is freely taken out off the assembly. Likewise the guide housing for push piece (2) is removed freely after push piece is taken out.

5


Disassembling Nozzle and Checking for Repair Use Maktest Injector Clamp (KO1495) to remove the Nozzle Holder.

Remove the Nozzle,

Be careful not to drop any small components.

7


Piston Type Spacer Remove the injector from the injector clamp, and make sure not to drop any pieces. Put all the components in a clean pan together with the injector. 1. Pins 2. Piston type spacer 3. Spring 4. Shim Make sure that all components from the same injector is put into the same pan. Do not mix the parts from different injectors.

Spacer in a Guide Type Remove the injector from the injector clamp, and make sure not to drop any pieces. Put all the components in a clean pan together with the injector. 1. Pins 2. Spacer 3. Guide 4. Spring 5. Shim Make sure that all components from the same injector is put into the same pan. Do not mix the parts from different injectors.

8


Checking For Repair

Check the injector body for corrosion. The nozzle holder should be screwed onto corrosion free threads. The surface should be free of cracks, dents and scratches (1). The injector bodies shown on the right cannot be repaired.

9


Dissembling the Solenoid and the Valve Group Mark the cable connection position with respect to the high pressure inlet using a permanent marker to be able to assemble the solenoid in the same position. Otherwise there may be connection problems when mounting the injector on the engine.

Use torque wrench to loosen the nut that mounts the solenoid on the injector body, The loosening torque should be less than 50 Nm. If the loosening torque is higher than 50 Nm, it is a sign of mistreatment before arriving for repair. Remove the nut completely, but the solenoid group is still tight because of the o-ring. Do not force to pull the solenoid sideways to remove it. Instead mount the nut back on the injector body and turn it just enough to grip the injector. Slightly turn and pull the solenoid group upwards until it is released.

Remove the spring (2) and the shim (1). Shim may be stuck in the solenoid hole. Make sure these items are not mixed with nozzle spring and shim.

10


Use tweezers to remove the sealing o-ring o ff the solenoid group.

The Washer (1) usually sticks to the solenoid and is removed off the assembly. If not please remove it using a tweezers from inside the injector body (a bove left figure). See below the magnet plate (1) is assembled with a lock piece on the valve mechanism. Magnet plate is the plate actually pulled by the solenoid to release the metal ball on the control valve. Magnet plate is supported with a spring. Push the magnet plate down and remove the lock nut. Hold the magnet plate firmly to control the spring underneath and lightly release the spring and remove magnet plate and the spring.

11


Use a torque wrench to remove the control valve nut. The loosening torque must be lower than 120 Nm. Any higher force needed to release the nut is a sign of mistreatment before arriving to repair.

Remove the nut, and take the rest of the valve mechanism out be careful not to drop the metal ball (4) and the ball holder (3), that may stick to the push pin (1). The stroke adjustment washer (2) may also stick to t he push pin.

12


Use Maktest Valve (KO1376) puller to remove the valve easily. Make sure to set the puller on top position before placing the puller inside the injector body to grip the valve. Turn the nut clockwise to clamp on the control valve. Pull firmly VERTICAL to remove the control valve out of the injector body. Do not try to pull by turning or sideways, as the injector body may be damaged to cause leaking. Be careful that the pin may come out together with the control valve.

Remove the high pressure seal (1) and its support ring (2) from the injector body.

13


Dissembling the Solenoid and the Valve Group CRI 2.1 Type (BMW applications) Mark the cable connection position with respect to the high pressure inlet using a permanent marker to be able to assemble the solenoid in the same position. Otherwise there may be connection problems when mounting the injector on the engine. Remove the solenoid group according to the instructions on “Dissembling the Solenoid and the Valve Group” on page 10.

Remove the valve pin (1) from the valve mechanism. Remove the adjustment shim (3) and then the pin guide (2) from the injector body.

14


Use tweezers to remove the metal ball holder and its holder.

Use a torque wrench to remove the control valve nut. The loosening torque must be lower than 120 Nm. Any higher force needed to release the nut is a sign of mistreatment before arriving to repair.

15


Use Maktest Valve (KO1376) puller to remove the valve easily. Make sure to set the puller on top position before placing the puller inside the injector body to grip the valve. Turn the nut clockwise to clamp on the control valve. Pull firmly VERTICAL to remove the control valve out of the injector body. Do not try to pull by turning or sideways, as the injector body may be damaged to cause leaking. Be careful that the pin may come out together with the control valve.

Remove the high pressure seal (1) and its support ring (2) from the injector body.

Dissembling the High Pressure Inlet Nipple Use a torque wrench to remove the inlet nipple. Loosening torque for inlet nipples with micro fiber inserts should be less than 150 Nm. Loosening torque for all other types of inlet nipples should be less than 120 Nm.

Checking Components for Repair

16


High Pressure inlet connection threads should be damage and corrosion free; otherwise there is a high risk of leaking (1).

High pressure nipple mounting surface should also be damage and corrosion free.

The solenoid body should be damage free and not heavily scratched. Example in picture (1) shows heavily scratched solenoid valve. Picture 2 shows the light damage that does not have any impact on its performance.

The connector socket should be damage free. Injector cable must be able to stay connected on the injector when it is mounted on the engine. Example (1) cannot be assembled on the engine.

17


The Solenoid fixing nut should not be damaged such that prevents to tighten the solenoid on the injector body. Example (1) cannot be assembled on the injector body.

Solenoid coil should not be damaged. Example (1) shows a damaged solenoid coil.

O-ring channel should be scratch free for complete sealing. Example (1) shows a scratched o-ring channel.

18


Damages on control valve ball seat causes high return and operation failures of common rail injector. Check the valve seat using a magnifier. The valve seat should be damage and scratch free for a normal operation. In any doubt change the valve. Example (4) shows a heavy damage on the valve seat. Example (3) shows also a heavy damage on the valve seat that causes high return. Example (2) has minor damage that does not affect the performance of the injector, yet change of the valve is recommended to avoid failures in the near future. Example (1) shows a new valve seat.

19


Assembling CRI Injectors Assembling the Valve Seal

Use the KO1509 High Pressure Seal Assembly Tool to mount the high pressure seal into the injector. (1) Push arm (2) Lock (3) Hub Release the both locks and turn the pull arm back as much as possible. Unscrew the knob on the push arm as much as possible.

Place the dummy seal (1) on the push arm end (2) Mount the hub on the injector, keeping the arm out of the injector. Screw the hub as much as possible and even tighten it with your hand without using any tools.

21


Push the arm (1) inside the injector.

Fix the arm position by tightening the lock screw (3). Turn the arm knob (1) until it touches the hub and cannot turn more.

Fix the knob lock screw (2) too. The hub (4) and the push arm (1) should look like as in t he picture above after setting the position of the seal on the tool. Unscrew the hub from the injector bo dy. Remove the dummy seal and put the new seal on the tool.

22


The seal (2) and the support ring (1) should look like as shown on the above picture. Make sure to place the support ring the cavity on the ring should face the seal to be able to support the seal.

Screw the hub in the injector body as much as possible and tighten it with your hand. Do not use any tools to tighten it. Push the arm into the injector body and feel the seal is placed in the injector body. Pull the arm back and unscrew the hub. The seal is placed to its housing inside the injector body.

23


Assembling the Control Valve

Place the valve (1) and the pin (2) in to the injector (3) as shown on the above picture. Use KO1510 control valve assembly tool to push the valve into the seal until it rests on its seat.

Screw the hub (2) as much as possible. Turn the push arm (1) slowly to allow the control valve to slide into the seal.

24


Assembling Valve Group of CRI 1.0, 2.0 and 2.2

Drop the ball (1) to its seat then place the ball holder on top of the ball.

Place the adjustment shim (1).

Place the push pin (1) on top of the adjustment shim and the ball holder.

25


Place the control valve fixing nut (1) in the injector. Make sure that the flat surface is facing the control valve. Screw the nut in and use KO1377 Valve Fixing Nut Wrench to tighten it. Use torque wrench for final tightening. Use below values for tightening fixing nuts in CR injectors type CRI 1, CRI 2.0 and CRI 2.1. Initial tightening: 38 Nm. Release angle must be larger than 30°. If it releases earlier, change the fixing nut. Fixing: 5 Nm (hand tight). Final tightening: 65 Nm (must be reached between 15 to 21°) Use below values for tightening fixing nuts in CR injectors type CRI 2.2 Initial tightening: 50 Nm. Release angle must be larger than 35°. If it releases earlier, change the fixing nut. Fixing: 5 Nm (hand tight). Final tightening: 65 Nm (must be reached between 16 to 22°)

Place the washer (1).

26


Daimler – Chrysler Engine Applications – Suspension Ring Assembly

Bosch has developed a suspension ring with an extra spring for Daimler – Chrysler. First place the spring (1) and then freely place the suspension ring on the spring (2).

Place the spring for the magnet plate over the push pin (1). Place the Magnet Plate over the push pin, on top of the spring. Push the magnet plate with your hand and place the lock piece to its slot.

Measuring and Setting the Magnet Plate Lift Before assembling the solenoid group, make sure that the mag net plate lift is set to the original value to be able to obtain the right delivery amount. Assemble the KO1381 Valve Lift Measurement Tool on the injector body as shown in the picture.

27


Mount the Dial Gauge with the long extension and reset it to zero.

28


Press the Dial Gauge to read the maximum allowed movement of the magnet plate.

Compare the value read with the original. Change the adjustment shim (2) shown below to set the lift to correct setting.

29


Measuring and Setting the Distance between Solenoid and Magnet Plate The distance should be set to 0.04 to 0.06 mm. Measure the Solenoid depth using KO1516. Use the tool as shown in the figure. Make sure to zero the dial gauge on an even surface to obtain maximum accuracy.

30


Measure the Magnet Plate depth using the KO1516. Use the tool as shown in the picture. Make sure to zero the dial gauge on an even surface to obtain maximum accuracy.

Deduct the height of the Magnet Plate from the Solenoid Depth to calculate the distance between solenoid and the magnet plate.

Change the shim (2) to set it between 0.04 and 0.06 mm.

31


Assembling the Solenoid Group

Place the solenoid spring, adjustment shim i nto the hole on the solenoid body.

Place the spring,

Put some lubricant to the threads of solenoid nut and injector body. 33


Place the solenoid vertically on the injector body and apply vertical force downwards while turning the solenoid slightly right and left. Do not try to turn the solenoid complete 360 degrees. Pay attention to the position of high pressure inlet with respect to the cable connection to avoid any mounting problems to the engine. Apply below procedures for tightening the solenoid: Initial tightening: 25 Nm. Release angle must be larger than 30°. If it releases earlier, change the solenoid nut. Fixing: 7 Nm (hand tight). Final tightening: 35 Nm (must be reached between 13 to 21°)

Assembling the CRI 2.2 type Solenoid and Valve Group (BMW Applications) Assemble the control valve seal and control valve and pin as per above instructions.

Place the fixing nut (2) and tighten it with your hand as much as possible. Use below values for tightening fixing nuts in CR injectors type CRI 2.2 Initial tightening: 50 Nm. Release angle must be larger than 35°. If it releases earlier, change the solenoid nut. Fixing: 5 Nm (hand tight). Final tightening: 65 Nm (must be reached between 16 to 22°)

34


Place the metal ball on the control valve.

Place the valve pin guide (1) freely on the fixing nut.

35


Place the adjustment shim (1) for the Valve Pin.

Place the Valve pin (1) into its guide.

36


Place the solenoid spring, adjustment shim into the hole on the solenoid body.

Place the spring,

Put some lubricant to the threads of solenoid nut and injector body. Place the solenoid vertically on the injector body and apply vertical force downwards while turning the solenoid slightly right and left. Do not try to turn the solenoid complete 360 degrees. Pay attention to the position of high pressure inlet with respect to the cable connection to avoid any mounting problems to the engine. Apply below procedures for tightening the solenoid: Initial tightening: 25 Nm. Release angle must be larger than 30°. If it releases earlier, change the solenoid nut. Fixing: 7 Nm (hand tight). Final tightening: 35 Nm (must be reached between 13 to 17°)

37


Assembling the Nozzle Assemble the parts as per the type of the injector following the procedures described bel ow:

Piston Type Spacer

Place the injector spring adjustment shim (4) into the injector body. Put the injector spring (3). Place the piston type spacer (2).

Measuring and Setting the Nozzle Lift of Injectors with Piston Type Spacers Assemble the KO1378 nozzle lift adjustment tool on the injector body. Make sure that the main hub is screwed completely down onto the flat end of the injector body.

Assemble the Dial Gauge and reset it to zero.

38


Screw the push pin down by turning the knob on the tool until it is blocked. Read the lift. Compare it with the original value.

Change the piston type spacer if needed. Place the pins and assemble the nozzle and the nozzle holder on the pins.

39


Use clamp to fix the nozzle on the pins.

Tighten the nozzle as per the procedure described below:

Tightening Torque Values for Injectors with Flat End

For Nozzle Holder 15 mm x 0,5 Initial tightening: 58-62 Nm. Release 120°.

Fixing: 5 Nm (hand tight). Final tightening: 33 – 50 Nm to be reached between 63 and 69 °


Fixing: 5 Nm (hand tight). Final tightening: 36 - 54 Nm to be reached between 43 and 49 °

40


Tightening Torque Values for Injectors with Maltese Cross End





Tightening Torque Values for Injectors with Butterfly End

For Nozzle Holder 15 mm x 0,5 Initial tightening: 36 - 44 Nm. Release 120°. Fixing: 5 Nm (hand tight). Final tightening: 26 – 45 Nm to be reached between 57 and 63 °

For Nozzle Holder 17 mm x 0,5 Initial tightening: 41 - 49 Nm. Release 120°.

Fixing: 5 Nm (hand tight). Final tightening: 35 - 53 Nm to be reached between 41 and 47°

41


Guided Shim Type Spacer

Place the injector spring adjustment shim (5) into the injector body. Put the injector spring (4). Place the Guide for the Shim (3). Place the shim inside the guide (2).

Measuring and Setting the Nozzle Lift Mount Dial Gauge on the KO1379 nozzle lift measurement tool. Use thin end extension, see picture.

Reset the Dial Gauge to zero on the flat surface of the KO1495 Injector Clamp.

42


Place the pins on the injector body.

Locate the tool on the pins and make sure that thin extension is placed into the guide and sitting on the shim.

43


Measure the value as a drop below the zero level and compare it with the original value. Change the shim if needed. Assemble the nozzle and the nozzle holder on the pins.

44


Use clamp to fix the nozzle on the pins.

Tighten the nozzle as per the procedure described below:

Tightening Torque Values for Injectors with Flat End




Fixing: 5 Nm (hand tight). Final tightening: 36 - 54 Nm to be reached between 43 and 49 °

45


Tightening Torque Values for Injectors with Maltese Cross End





Tightening Torque Values for Injectors with Butterfly End




Fixing: 5 Nm (hand tight). Final tightening: 35 - 53 Nm to be reached between 41 and 47°.

46


Testing the Injectors and Interpreting the Results Below test should be done after assembling the injector as per instructions above, and making sure that the dimensions in assembly has been adjusted according to the specifications of the injector. Standard test consist of 6 steps: 1. Warm-up, injector is run at this stage for a certain amount of time, depending on the delivery of the injector. Higher the delivery makes the injector warm up time shorter. 2. Leak test, injector is exposed to high pressure without the sending any signals to run the injector. This is for testing the leakage from a. Seal, b. Control valve and piston surface c. Control valve ball seat surface. d. General assembly of the injector Return test oil amount is measured and compared with the target values. If the result is higher than specified target limits, the test should be stopped and there is no need to test the remaining steps. 3. High Pressure Delivery Test is for determining t he condition of the nozzle. The amount being delivered may be less. This means that the nozzle holes have been narrowed due to wear o ut. The delivery may be higher, presenting a sign of wear out in ball seat, causing extensive injection time. This should also be compared with the return value, as this case will increase the return test oil amount too. The delivery may be acceptable but if the return is higher, there is a high possibility of high test oil return from the nozzle (provided that the leak test was acceptable). 4. Low Pressure Delivery Test is for determining the nozzle condition at low pressure. The amount is expected to be lower than if the nozzle holes are narrowed. If the delivery is higher than the limits, the nozzle seat is worn out and leaking even after the injection is ended. 5. Spray test with high pressure is for determining the spray pattern and angles. 6. Spray test at low pressure is for determining the leaking at low pressure, in case the nozzle needle is not sealing off the test oil after the injection is ended. Visual check is necessary to determine this factor and stop the knocking sound at idling.

47


Fine Tuning the Delivery of Common Rail Injector If the injector is slightly off the limits, it can be adjusted to fit into the limits. This is often needed when using different brand spare parts and nozzles.

Which part has what affect on the deliveries? Ball Lift Ball lift must be adjusted when assembling the injector. Mechanical dimension check is usually enough to make sure that the ball lift is regulating the pre-injection correctly. Change the thickness of the shim (1) shown in the figure to adjust the ball lift. As the setting of ball lift is possible with measurement only, the pre injection test is not necessary on the test bench. However a preinjection delivery test can be generated. Please refer to section “creating your own test plans”. Higher the Ball Lift setting is higher the pre injection delivery.

Distance between the Solenoid and the Magnet Plate Distance between the solenoid and the magnet plate is the first setting for all delivery levels at all pressures. The induction power on the magnet plate affects the response behavior of the injector to the signal. If this distance is too close it damages the solenoid, if this distance is too far, the delivery levels are low and target levels cannot be met. This distance should be adjusted to 0,04 – 0,06 mm to able to have a most effective performance. This distance also changes the current that the solenoid withdraws from the ECU. Therefore if this distance is set too far, the current to pull the magnet plate will be higher and will cause the ECU to generate fault after a while. Adjust the distance with changing the thickness of the washer (2) shown in the figure to adjust the distance. Higher the distance is lower the delivery at especially middle pressure levels.

Thickness of the Solenoid Shim Solenoid shim thickness changes the load for the solenoid to overcome at the start of the injection. The thinner shim causes the injector to open fast and close slow, increasing the deliveries at all pressure levels. Thicker shim is causing the solenoid to act late but close fast, and reduces the delivery at a ll pressure levels. Like all other settings, thickness o f this shim can be c hanged within some certain limits, and o utside of these limits causes the injector behave unpredictable.

49

61 Bosch Cri Repair Instructions En

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