TM 5-3895-359-14&P
TROUBLE SHOOTING CHARTS (Noodle Valve Injectors)
INCORRECT INJECTOR OUTPUT
Probable Cause
1. SPRAY TIP OR ORIFICES
8. CRACKED CHECK VALVE CAGE,
PARTIALLY PLUGGED
SPRING CAGE OR SPRAY TIP
2. SPRAY TIP ORIFICES ENLARGED
9. CRACKED BUSHING
3. CARBON BUILD-UP IN SPRAY TIP
10. IMPROPERLY LAPPED SURFACES
4. WORN PLUNGER AND BUSHING
11. FOREIGN MATERIAL BETWEEN
VALVE AND SEAT
5. WORN OR DAMAGED NEEDLE
12. RACK AND GEAR NOT IN TIME
VALVE QUILL
6. WORN OR DAMAGED NEEDLE
13. SPRAY TIP - PLUNGER AND
VALVE SPRING SEAT
BUSHING COMBINATION
PROVIDES INCORRECT OUTPUT
SUGGESTED REMEDY
7. WORN OR BROKEN VALVE SPRING
1. Clean the spray tip as outlined under Clean Injector
5. Replace the needle valve and spray tip assembly.
Parts.
6. Replace the spring seat.
2. Replace the needle valve and spray tip assembly.
7,. Replace the valve spring.
3. Clean the spray tip with tool J 1243.
8. Replace the cracked parts.
4. After the possibility of an incorrect or faulty spray tip
9. Replace the plunger and bushing assembly.
has been eliminated and the injector output still does not
fall within its specific limits, replace the plunger and
10. Lap the sealing surfaces.
bushing with a new assembly.
11. Disassemble the injector and clean all of the parts.
NOTE: The fuel output of an injector varies with
the use of different spray tips of the same size
12. Assemble the gear with the drill spot mark on the
due to manufacturing tolerances in drilling the
tooth engaged between the two marked teeth on the
tips. If the fuel output does not fall within the
rack.
specified limits of the Fuel Output Check Chart,
try changing the spray tip. However, use only a
13. Replace the spray tip and the plunger and bushing
tip specified for the injector being tested.
assembly to provide the correct output.
10-3-61
