Injection Nozzles

NOTE: If engine has excessive knock, an injector needle may have seized. Accelerate engine several times without load. If this does not eliminate noise, injector nozzle must be replaced. Defective injector can be found by unscrewing each injector line (one at a time) until noise stops.

Remove high pressure fuel injection and fuel return lines. Using a Nozzle Socket (T84P-9527-A), remove fuel injectors from engine.
NOTE: Use ONLY SAE-approved calibration oil (208629), SAE (J967D), or ISO fluid (4173), to test fuel injectors.
After filling nozzle tester (014-00300), with calibration fluid, connect injector to high pressure line of tester. See Fig 1 . Bleed air from line, and injector, by pumping tester handle several times.

Fig 1: Injection Nozzle Tester
Check spray pattern test by operating tester lever in short fast strokes. Injector must have a tight cone-shaped pattern and fuel stream should break off sharply at end of each stroke. See Fig 2 .

Fig 2: Fuel Injector Spray Patterns

NOTE: A small amount of internal leakage is designed into each injector for lubrication purposes.
Operate tester lever slowly and completely (1-2 strokes per second). A "chatter" sound will occur if injector is operating properly.
Check pressure by operating tester lever and observing pressure at which injector begins to spray.

Check valve seat sealing by applying 200 psi (14 kg/cm² ) below injector opening pressure, for 10 seconds. The injector must not drip.

INJECTOR NOZZLE PRESSURE TEST SPECIFICATIONS

Application	Pressure: Psi (Kg/cm² )
Normal Injector	1957-2291 (138-161)
Difference Between Injectors (MAX.)	218 (15.3)

If fuel injector leaks, or has incorrect spray pattern/opening pressure, it must be replaced. Injectors cannot be repaired.

NOTE: The injector nozzle holding nut has a copper seal which must be replaced when nozzle has been removed.