3-2. FUEL SYSTEM MAINTENANCE (CONT)
a. Fuel Injector Nozzles (Cont ) .
TESTING (SHEET 3 OF 3)
(8) Check fuel injector spray pattern as follows:
(a) Disconnect fuel injector from upper discharge fitting and connect to lo-
wer discharge fitting.
(b) Close gage valve.
Fuel injector will chatter when tester is operated rapidly. Chatter is
an indication of valve freedom, good seat width, and interference angle.
This chatter can change between fuel injectors. Chatter between fuel
injectors must not be compared for purpose of making fuel injectors
acceptable or not acceptable.
FINE ATOMIZED SPRAY PATTERN
SOLID IRREGULAR SPRAY PATTERN
(c) Operate tester at 60 strokes per minute and watch spray pattern. If
spray pattern is finely atomized, fuel injector is operating properly.
If spray pattern is solid and irregular, notify general support mainte-
nance (fuel injector must be repaired).