Injection Nozzles

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

Remove the high pressure fuel injection and fuel return lines. Using a Nozzle Socket (T84P-9527-A), remove the fuel injectors from the engine. Test the injectors (one at a time) on a Nozzle Tester (014-00300 or equivalent).
NOTE: Use ONLY SAE-approved calibration oil (208629), SAE (J967D), or ISO fluid (4173), to test the fuel injectors.
Once the injector nozzle has been connected to the high pressure line of the tester, bleed the air from the line and nozzle by pumping the tester handle several times. Check spray pattern test by operating tester lever in short fast strokes. Check that the injector has a tight cone-shaped pattern and that the fuel stream breaks off sharply at the end of each stroke. See Figure .
Operate tester lever slowly and completely (1-2 strokes per second). A "CHATTER" sound will occur when the nozzle is operating properly.

Check pressure by pressing on the tester lever and observing the pressure gauge when the injector begins to spray.

INJECTOR NOZZLE PRESSURE TEST SPECIFICATIONS

Application	Pressure Psi (Kg/cm² )
New Injector	2059-2291 (145-161)
Minimum Allowable Injection	1957.5 (137.6)
Maximum Difference Between Nozzles	145 (10.2)

Check valve seat sealing by pressing down on tester lever and holding it for 10 seconds at approximately 1885 psi (133 kg/cm² ). The nozzle must not drip. If the fuel injector leaks, is defective, has the wrong spray pattern, or the wrong opening pressure, replace it. Injectors cannot be repaired.

NOTE: The injector nozzle holding nut has a copper seal which must be replaced when the nozzle has been removed. Apply anti-seize compound to the injector threads before installation.