Checking injection nozzles

07.1—135 Checking injection nozzles

Job no. of flat rates or standard texts and flat rates data 07—6712.

Test values injection nozzles

) The difference between any two injection nozzles within one engine must not exceed 5 bar positive.

) Starting production code no. 928 or 041.

) Starting November 1981 with center bore 0.20 mm dia. (formerly 0.15 mm dia.)

Nm

Cleaner

000 589 00 68 00

Torque wrench 1/2″ drive, 40-130 Nm

Tester EFEP 60 H

e.g. Bosch, D-7000 Stuttgart Order No. 0 681 200 502

Cleaning needles 0.13 mm dia.

e.g. Bosch, D-7000 Stuttgart Order No. KDEP 2900/3

Cleaning needles 0.18 mm dia.

e.g. Bosch, D-7000 Stuttgart Order No. KDEP 2900/5

For testing always use clean testing oil or filtered diesel fuel. Be sure never to hold your hand in the jet from an injection nozzle. For the jet would penetrate your skin, destroy the tissue beneath, enter your bloodstream and possibly give you blood poisoning.

07.1.8-135/1 F3

Be sure to close the pressure gage tap for checking jet and rattling noise because pressure gage may otherwise be damaged by excessive increase in pressure.

The engine is equipped with a center hole pintle nozzle which is distinguished from the standard pintle by a cross hole and a center hole (14 and 15) in the thrust pin. Moreover, a maintenance-free edge filter (13) is pressed into upper part (7) of the in­jection nozzle holder.

1    Needle valve

2    Nozzle body

3    Nozzle holder insert

4   Thrust pin

5    Injection nozzle holder, lower part

6    Compression spring

7    Injection nozzle holder, upper part

8    Leak-off connection

9    Fuel inlet

10    Steel shim

11    Annular groove and inlet ports

12    Pressure chamber in nozzle body

13    Edge filter

14    Cross hole

15    Center hole

1    Prior to checking: Check center hole (47) with cleaning needle of 0.18 mm dia. for passage. On nozzles with 0.15 mm ID, check pintle with cleaning needle 0.13 mm dia. for passage.

2   Thoroughly pump injection nozzle 5 times on tester. Then check buzzing, actuating hand lever slowly for this purpose (at least 1 stroke per second).

3 Check jet: At short, fast partial strokes (at least 2 strokes per second) the jet must be rather closed and break well.

A Jet pattern closed and well atomized

B Jet pattern torn up, too wide and spreading

07.1.8-135/2 F3

4 Establish initial jet by moving hand lever slowly down (4—6 s/stroke).

A vertical cord-like jet must come out of center hole (15).

Note: On new nozzles, the initial jet is very difficult to produce, for this reason check center hole with cleaning needle 0.18 mm dia. for passage.

5 Checking ejection pressure:

Nominal value: 135—143 bar with new nozzle, at least 120 bar with used nozzle.

At slow downward movement of hand lever (approx. 1 stroke per second) read ejection pressure on pressure gauge.

Shutoff valve must be open for checking.

07.1.8-135/3 F3