Programmed Repairs: Diesel fuel injection Engines 602.96, 603.96/97 TURBO

Programmed Repairs Engines 602.96, 603.96/97 Combustion

Remedy

Run engine at idling speed.

Unplug 2-pin connector (arrow) at servomagnet (Y22).

If engine runs properly, check idle speed and set, if necessary, to 58020 rpm.

Install modified control module

part no. 006 545 36 32 and plug in 2-pin connector again.

P07-6354-13

Note

Coding bridge of old control module must not be plugged into the new control module.

When inserting the new control module, pierce the non-assigned contact 5 in the connector (arrow).

P07-6357-13

Cause

Excessive sheer of petrol in diesel fuel. Not more than 20% regular grade petrol is approved at

temperatures below -23 °C; i.e., it is not necessary to add petrol at temperatures higher than -23 °C.

Cause

Injection pump suction chamber runs dry. Internal leak. Vapor bubbles visible at fuel feed.

Remedy

Check fuel flow filter for leak, replace if necessary.

Check connections of top part of filter for leaks and vent drilling for fuel return flow for blockage.

Check overflow restrictor at injection pump return. Check injection pump for leak: fuel tank  1/4 full. Lift up front of car about 40 cm, no vapor bubbles should be visible in the fuel feed pipe, and also not in the fuel return pipe of the injection pump, within 10 min with engine switched off; replace injection pump if necessary.

Cause

Fuel pump draws in air.
Remedy

Install fuel tank with splash pot.

Fuel tank

Cause

Fluid level in oil sump too high.

Remedy

Check engine oil level, adjust to correct level if necessary; perform oil change if necessary.

Cause/Remedy

 Vacuum hose and vacuum pump (67) may be split.

 Filter (62) blocked or leaking.

 Restrictor (61b, orange) may be blocked.

 Vacuum of vacuum pump not sufficient. Check vacuum at ancillaries connection. Specification when engine idling after 30 s at least 700 mbar.

P07-6356-55

Cause

Results from operation of AJC.

Remedy

Install AJC control module with designation RO2 (was RO1). Part number unchanged. Standard equipment as of end 04/88. No further remedy possible.

Note

Engine does not vibrate when idling, no noises evident, compression and pressure loss in order. Fuel filter not blocked.

Cause

Exhaust or inlet valve spring broken.

Remedy

Replace valve spring.

Cause

Deceleration damper has insufficient effect.

Remedy

Install damper 601 070 13 67.

In critical cases the reinforced tension/compression damper 601 070 14 67 can also be installed.

Cause

Pump governor group jamming briefly (centrifugal element in governor of injection pump).

Damage code for warranty/goodwill cases: 07 013 15

Remedy

Replace injection pump.

Cause

Boost pressure too high or engine overload protection activated too soon.

Remedy

Test boost pressure with connector unplugged from engine overload protection switch (S66).

If boost pressure >0.95 bar, boost pressure control valve of turbocharger faulty. Replace turbocharger.

If boost pressure <0.95 bar, switch engine overload protection (S66) reacting too soon. Replace switch (S66).

P07-6355-13

Cause

Rubber connection pipe at hose straps split and as a result the barometric pressure compensation unit is not pressurized with boost pressure.

Remedy

If no boost pressure exists at barometric pressure compensation unit, inspect pressure pipes for leaks and replace damaged rubber connection pipes.

Note

Do not overtighten hose clips.

Remedy

Install injection pipes with double cone.
Ensure the plastic clips are correctly installed.

Cause

Damaged piston vacuum pump (model up to May 1986).

Remedy

If this problem exists on models manufactured prior to this date, which do not have a second drilling in the oil spray nozzle for the oil supply of the piston vacuum pump, or for performing work which requires taking off the vacuum pump, remove the centering sleeve and install in modified seal for improving the oil supply.

Procedure

1 Remove flange shroud, fan and belt (see Repair Instructions Group 13, Op. No. 342).

2 Remove piston vacuum pump (see Repair Instructions Group 43, Op. No. 618).

3 Remove centering sleeve (3). It must no longer be installed.

Note

The centering sleeve should be installed as an aid when removing the injection pump. It prevents the injection timing device jamming when cranking the engine.

P43-2001-13

4 Install modified seal (10) in place of the previous one.

5 When dealing with the problem mentioned above, install new vacuum piston pump.

6 Do not connect vacuum pipes to the brake unit at the piston vacuum pump at this stage.

7 Install V-belt, fan and fan shroud.

8 Run engine and pour about 50 cm3 engine oil into the piston vacuum pump through the open vacuum connection with an oil spray can.

P43-2002-13

9 Connect the vacuum pipe to the brake unit immediately.

Refer to the microfiche "operation texts and work units" under Op. No. 43-0610 for the work units.

Production breakpoint of second drilling in oil spray nozzle: May 1986

Cause

Overshooting of AJC servomagnet causes quantity reduction.

Remedy

Install AJC control module with the designation RO2 (was RO1), part no. unchanged.

Standard equipment as of end 04/88. Adjust AJC control with 2.4 kW or 4.7 kW reference resistor

(see RA07.1-1841, pages 13, 14).

Remedy

Install gasket at turbocharger flange.

Cause

Idle speed setting at injection pump not correct.

Remedy

Remove injection pump and set on injection pump test bench. The setting is described in the Bosch microfilm W400/00 under "Reducing idle speed stage of MB cars with EP combination M/RSF II Engine 602 and TURBO".

Note

Injection pumps as of production date 069 are no longer affected by this problem.

Remedy

Remove EGR valve, replace, install. In addition on engines 602.96, 603.96:

Remove vacuum pipe to EGR valve. Replace, install. Remove connection piece between EGR switchover valve and vacuum pipe, replace, install.

Damage code: 14 315 36

Cause

Different compression of individual cylinders (as of about 3 bar).

Note

Replacing the injection nozzles does not offer a remedy.

Remedy

Test cylinders for leaks (Repair Instructions Group 01, Op. No. 015), and rectify any leaks.

Remedy

Set start of delivery to 13° after TDC (GIM method with digital tester).

Replacing injection nozzles does not offer any remedy.

No further remedy possible.

Cause

Axial play of injection timing device.

Diagnostic note

Noise is easily assigned to the injection pump governer.

Remedy

Remove injection timing device, replace, install

(see 07.1-8014).

Damage code: 07 111 36

Cause

ESC control module.

Remedy

1 Read fault memory.

2 Test ESC (see 07.1-2006), testing, adjusting idling speed (see 07.1-2053).

3 Install ESC control module with software 10/94 and green dot identification or as of production date 41/94.

Remedy

Replace EGR pipe.

Note

Install new version of EGR pipe.

Damage code: 14 305 06

Cause:

Boost air pipe and mixing chamber coked.

Fault code output: EDS control module 

Remedy:

Test vacuum transducer Y31/1 and boost pressure shutoff switchover valve Y31/6 (see RA07.1-1120).

Note:

When performing test step 5.1 of RA 07.1-1120, 11-14V are measured only if short circuit or fault in boost pressure control circuit, otherwise 0.3 - 0.5V.

If no fault can be found, remove boost air pipe and mixing chamber, clean, install.

Damage code: 09 340 24

Remedy

Install tension/compression damper (strengthened version).

Cause

Excessive idle quantity variation of injection pump.

Note

Replacing engine mounts and injection nozzles does not provide any remedy.

Remedy

Set synchronization of injection pump (<0.5 mm3/stroke) on injection pump test bench.

Damage code: 07 001 XX setting synchronization.

Cause

a) Full load stop not correctly set.

b) Insufficient full load quantity.

Remedy

a) Check setting of accelerator control linkage, adjust (see RA30-1010).

b) 1 Remove boost air pipe, install (see

RA14-1310).

2 Set full load quantity at barometric pressure compensation unit:

- Take off cap (black) on barometric pressure compensation unit (103).

- Slacken lock nut (103d).

- Use a screwdriver to turn setting screw about 1/4 turn to the left.

- Tighten lock nut (103d).

- Fit on cap.

P07.11-0003-02

Cause

The boost pressure control is switched off by the EDS control module because of a delay in operation of the switchover valve (Y27/5).

Note

After switching off engine or ignition: switching off, on eliminates the problem briefly but does not rectify the cause.

Remedy

Remove switchover valve (Y27/5), replace, install.

Damage code: 54 485 XX delay switch.

Cause

Vapor bubbles in fuel pipes.

Damage code: 82 815 XX

Remedy

1 Replace check valve.

2 Convert fuel pipes upstream and downstream of check valve (because of installation position).

Cause

Control module recognizes "no connection at output stage".

Remedy

Ignore fault code.

Note

Control modules as of manufacturers date of production 168 in order.

Remedy

1 Check full load stop, adjust

(see RA 07.1-1100).

2 Perform speedometer comparison on roller dynamometer (see RA 07.1-1203).

Note

Perform speedometer comparison at about

160 km/h. If the difference is not within tolerance, calibrate speedometer.

3 Test start of delivery (see RA 07.1-8240,

RA 07.1-8244).

4 Adjust start of delivery (see RA 07.1-8300).

5 Test max. engine speed at no load

(see RA 07.1-1203).

6 Set max. engine speed to top tolerance limit by turning hexagon socket bolt (2m) to the right.

Note

1/2 turn equals 150 rpm.

7 Test full load CO (see RA 07.1-1203). If full load quantity is < 0.1%, increase the full load quantity.

Note

On models with the exhaust gas recirculation (Code 620), it is not possible to measure full load CO at the tailpipe. A single adjustment should be performed. If this does not result in any increase in engine output, continue with step 9.

8 Increase full load quantity.

a) Engines without anti-jerk control (AJC):

- Turn slotted screw (2f) about 1/4 turn to the left.

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b) Engines with anti-jerk control (AJC):

- Remove AJC servomagnet (Y22/3) and flange.

Note

Use T30 Torx. Screws are microencapsulated.

- Slacken lock nut of sliding pin (2y).

- Turn sliding pin (2y) about 1/4 turn to the left.

- Tighten lock nut of sliding pin (2y).

- Bolt on flange and insert servomagnet (Y22/3) without O-ring (162).

Note

When inserting servomagnet, no resistance should be felt; shorten lift rod (163) of servomagnet (Y22/3) up to max. 0.3 mm if necessary.

- Install servomagnet (Y22/3) with O-ring (162).

- Check injection pump for leaks.

9 Models with exhaust gas recirculation
(Code 620):

- Remove injection pump, install
(see RA 07.1-8410).

- Set injection pump on injection pump test bench.

P07.11-0002-15