3-50. INJECTION NOZZLE REPAIR/TESTING (CONT)
Orifice Restriction Testing
Close gage protection valve.
Close on-off valve.
Open pump isolation valve.
When-fluid flows from nozzle tip, discharge should be the same through all six orifices. Any
difference, either vertically or horizontally, indicates a bad nozzle.
Slowly increase pressure. Watch orifice discharge pattern. If spray pattern is incorrect, replace nozzle.
Do not use steel brush or wire wheel to clean nozzle body or nozzle tip. Use of these tools can
cause small reduction of orifice size, and this will cause large reduction in engine horsepower.
Using brass brush, remove loose carbon from nozzle tip.
Remove injection nozzle from tester.