Checking Injection Nozzles
CHECKING INJECTION NOZZLESTest values injection nozzles
Injection pressure in bar positive
for new injection nozzles 135-143
for used injection nozzles, min. 120
Tightening torques
Injection nozzles, upper and lower parts 70-80 Nm (52-59 ft lb)
Special tools
Conventional tools
Torque wrench 1/2" drive, 40-130 Nm
Tester EFEP 60 H
Cleaning needles 0.13 mm dia.
Cleaning needles 0.18 mm dia.
WARNING: 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.
Attention: 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.
Checking
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.
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.