Trouble Shooting (Needle Valve Injectors) 2.0
DETROIT DIESEL 53
Chart 6
S U G G E S T E D REMEDY
5. Replace the needle valve.
1. Clean the spray tip as outlined under Clean Injector
Parts
6. Replace the spring seat.
2. Replace the spray tip assembly.
7. Replace the valve spring.
NOTE: The fuel output of an injector varies
8. Replace the cracked parts.
with the use of different spray tips of the same
size due to manufacturing tolerances in drilling
9. Replace the plunger and bushing assembly.
the tips. If the fuel output does not fall within
the specified limits of the Fuel Output Check
10. Re-lap the sealing surfaces.
Chart, try changing the spray tip. However, use
only a tip specified for the injector being tested.
11. Disassemble the injector and clean the parts.
3. Clean the injector tip with tool J 1243.
12. Assemble the gear with the drill spot mark on the
tooth engaged between the two marked teeth of the
4. After the possibility of an incorrect or faulty tip has
rack.
been eliminated and the injector output still does not
fall within its specific limits, replace the plunger and
bushing with a new assembly.
SEC. 2.0 Page 11
August, 1972