ARMY TM 9-2815-260-24
AIR FORCE TO 38G1-126-2
MARINE CORPS TM 09244A/09245A-24
Fuel injection nozzle should chatter softly, and spray pattern should be broad and finely
atomized. Replace fuel injection nozzle if it fails to chatter.
Using pumping rate for proper atomization, operate tester for ten strokes. Fuel injection
nozzle must atomize on at least eight of the ten strokes without consecutive misses. If
nozzle fails to meet requirement, repeat procedure. Replace fuel injection nozzle if it fails
on second test.
Perform spray pattern test as indicated below:
Operate nozzle tester at a pumping rate that will cause fuel injection nozzle to chatter.
Observe spray pattern of three orifices and check for plugged orifices. Replace fuel
injection nozzle if spray pattern angle is incorrect or if spray pattern is streaky instead of
Perform leakage test as indicated below:
Position fuel injection nozzle on nozzle tester with nozzle tip down.
Operate pump handle rapidly to firmly seat valve. Wipe nozzle tip dry with a clean, lint
Slowly raise pressure on test gauge to 400-500 psi (2800-3500 kPa) below opening
pressure measured in step 5.
Watch for accumulation of fuel around all three fuel injection nozzle tip orifices. Replace
fuel injection nozzle if fuel drips from fuel injection nozzle within 5 seconds.
Perform valve stem and guide wear test as indicated below:
Fuel from spray orifices can penetrate clothing and skin and cause serious
personal injury. Always direct fuel injection nozzle tip away from
personnel. Always enclose fuel injection nozzle in a transparent cover.
Failure to comply could result in serious personal injury.
Position fuel injection nozzle with tip slightly above horizontal plane.
Slowly raise pressure on test gauge to 1500 psi (10300 kPa).
Leakage rate based on use of No. 2 diesel fuel or an equivalent viscosity of
test oil at 65 to 75° F (18 to 24° C).
Check for leakage from return end of fuel injection nozzle. After one drop, leakage
should be 3-10 drops in 30 seconds. Replace fuel injection nozzle if not within specified