3-50. INJECTION NOZZLE REPAIR/TESTING (CONT)
Check pressure gage. It should show 2,200 psi when pump isolator valve is closed.
Wait 30 seconds, then read pressure gage. Pressure loss should be:
200 psi minimum
1,800 psi maximum
If pressure loss is not within this range, stop the test. Replace nozzle. If it is within this range, perform valve
opening pressure test (subpara d).
Valve Opening Pressure Testing
Open pump isolation valve one-half turn.
Operate pump to increase pressure slowly until fuel comes from nozzle tip. Check gage.
Reading on gage should be 2,400-3,100 psi.
If valve opening pressure is not within this range, stop test. Replace nozzle. If it is within this range, flush nozzle
Close gage protection valve.
Close on-off valve.
Operate the pump rapidly for three full strokes.
Tip Leakage Testing
Using rag, remove all fuel from nozzle tip and adapter. Make sure nozzle tip is completely dry.
Open gage protection valve.
Pump and hold pressure of 2,200 psi for 30 seconds. Watch tip of nozzle. A drop may form but should not fall
from nozzle tip.
If nozzle tip drips, stop test. Replace nozzle.
If nozzle passes test, perform orifice restriction test (subpara g).