TM 5-3805-281-24-2
Fuel System
DIAGNOSE INJECTION NOZZLE
MALFUNCTION
Problem
Possible Cause
Suggested Remedy
Failed Carbon Stop Seal Washer
Nozzle replaced without using new seal or
Install new washer.
washer.
Incorrect Opening Pressure
Improper adjustment.
Adjust opening pressure.
Broken spring.
Replace spring.
Nozzle Will Not Open
Plugged orifices.
Clean.
Chipped orifices.
Replace nozzle.
Bottomed lift screw.
Adjust lift screw.
Poor Spray Pattern
Plugged orifices.
Clean.
Chipped orifices.
Replace nozzle.
Cracked nozzle tip.
Replace nozzle.
Poor Atomization
Plugged orifice.
Clean.
Chipped orifice.
Replace nozzle.
Cracked nozzle tip.
Replace nozzle.
Valve not free.
See "Inconsistent Chatter".
Inconsistent Chatter
Spring components misaligned.
Adjust opening pressure.
Varnish on valve.
Clean guide area.
Deposits in seat area.
Clean seat.
Bent valve.
Replace nozzle.
Distorted body.
Replace nozzle.
No Chatter
Spring components misaligned.
Adjust opening pressure.
Varnish on valve.
Clean guide area.
Deposits in seat area.
Clean seat.
Bent valve.
Replace nozzle.
Valve seat eroded or pitted.
Lap valve to seat. Replace nozzle as
necessary.
Tip seat pitted.
Lap tip to seat. Replace nozzle as necessary.
Seat interference angle worn.
Replace nozzle.
Distorted body.
Replace nozzle.
Seat Leakage
Deposits in seat area.
Clean seat.
Valve seat eroded or pitted.
Lap valve to seat. Replace nozzle as
necessary.
Tip seat pitted.
Lap tip to seat. Replace nozzle as necessary.
Valve not free.
See "Inconsistent Chatter".
See "No Chatter".
Distorted body.
Replace nozzle.
Cracked tip.
Replace nozzle.
High Leak-Off
Wear or Scratched at Guide
Lap valve to guide. Replace nozzle.
Low Leak-Off
Varnish on valve.
Clean guide area.
Insufficient clearance.
Clean nozzle. Lap valve to guide. Replace
nozzle as necessary.
RG,RG34710,1302
1923OCT971/1