Page 769 of 2053
1F3 -- 12 OM600 ENGINE CONTROLS
D AEW OO M Y_2000
VACUUM PUMP
Preceding Work : Remove the poly V-- belt
1 Bolt 10N∙m (89 lb-in) .....................
2 Vacuum Pump3 Vacuum Line
4 Gasket Replace..........................
Page 770 of 2053
OM600 ENGINE CONTROLS 1F3 -- 13
D AEW OO M Y_2000
Removal & Installation Procedure
1. Remove the vacuum line.
2. Remove the bolts (1) evenly.
Notice
If necessary, rotate the engine until the pressure on
the tappet of the vacuum pump is released.
3. Remove the vacuum pump (2).
4. Install the vacuum pump (2).
Tightening Torque10 N∙m(89lb-in)
Notice
Clean the gasket residues of sealing surface of vac-
uum pump and replace the gasket(4).
5. Connect the vacuum line.
Page 771 of 2053
1F3 -- 14 OM600 ENGINE CONTROLS
D AEW OO M Y_2000
VACUUM UNIT REPLACEMENT
1 Bracket
2Bolt
3 Vacuum Unit
4 Vacuum Line
5 Seal Replace.............................
Page 772 of 2053
OM600 ENGINE CONTROLS 1F3 -- 15
D AEW OO M Y_2000
IDLE SPEED ADJUSTMENT
Service Data
EngineIdle Speed
OM661LA Engine750 -- 850 rpm
OM662LA Engine720 -- 820 rpm
Tools Required
667 589 00 21 00 TDC Pulse Generato
Commercial Tool
Digital Testere.g. Bosch, MOT 001.03g
Sun, DIT 9000
Adjustment Procedure
1. Connect the digital tester (1) and TDC pulse sender
unit (11).
2. Run the engine and warm up the coolant to
60~80_C.
TDC pulse generator 667 589 02 21 00
3. Disconnect the vacuum hose (4) from the PLA unit
to check idle speed with tester.
4. Check idle speed with tester.
OM 661LA Engine750 -- 850rpm
OM 662LA Engine720 -- 820rpm
Notice
To adjust idle speed, loosen the locking nut (6) of
PLA unit.
Page 773 of 2053
1F3 -- 16 OM600 ENGINE CONTROLS
D AEW OO M Y_2000
5. Ensure not to damage the idle spring in the governor
and adjust idle speed by turning the PLA unit (5)
slowly.
ClockwiseRPM Decrease
CounterclockwiseRPM Increase
Notice
Do not rotate the PLA unit over 1/2 turn from the
position marking. If do, idle spring in the governor
will be severely damaged.
6. After adjustment, tighten the locking nut and place
the position marking with different color of paint.
Notice
If there are no changes in idle speed with PLA unit
adjustment, perform the service at a BOSCH Ser-
vice Center.
7. Connect the vacuum pump to the PLA vacuum unit
and build up vacuum approx. 500mbar. If engine
rpm increases by approx. 100rpm, It is normal.
Vacuum Pump 001 589 73 21 00
8. Connect the vacuum line (4).
9. Switch on all ancillaries and check the idle speed.
Page 774 of 2053
OM600 ENGINE CONTROLS 1F3 -- 17
D AEW OO M Y_2000
FUEL PUMP TEST
Notice
Before test, replace the fuel filter cartridge and fuel pre-
filter.
Fuel Feed Test
1. Disconnect the fuel return line (1) and seal up it with
plug.
2. Insert the plastic hose (5) and put the end into the
measuring beaker (6).
3. Disconnect the vacuum line (4) from vacuum unit
(engine stop) (5) and connect the vacuum pump (7)
to the vacuum unit.
4. To avoid the engine starting, build up vacuum
(approx. 500 mbar).
5. Operate the starter motor for exactly 30 seconds
and measure fuel volume in the beaker.
Min. volume150cm3for 30 seconds
Page 775 of 2053
1F3 -- 18 OM600 ENGINE CONTROLS
D AEW OO M Y_2000
Fuel Pressure Test
Page 776 of 2053
OM600 ENGINE CONTROLS 1F3 -- 19
D AEW OO M Y_2000
Tools Required
617589042100 Tester
1. Disconnect the fuel line (2) from the fuel filter.
2. Remove the banjo bolt (4) from the fuel injection
pump and remove the seals (3) and fuel line (2).
3. Connect the tester (5).
4. Start the engine and read off the fuel pressure on
tester (5).
Notice
At Idle Speed> 0.3bar
At Full load> 0.5bar
If out of standard, replace the fuel feed pump.
Tester 617 589 04 21 00
5. Stop the engine.
6. Remove the tester.
7. Replace the seal and connect the fuel line (2).