TM 5-3810-300-24&P-3
Fuel Injector
2.1.1
including the check valve cage, spring, spring seat, spring
CAUTION: Make sure lever 4 is in the
cage and spray tip assembly.
down position before operating pump lever
1.
2. Carefully pilot the injector nut over the spray tip and
valve parts and thread it onto the adapter (Fig. 14).
3. Operate pump lever I to build up to 1600 to 2000 psi on
gage 1. Check for leakage at the injector filter cap gaskets,
3. Tighten the injector nut.
body plugs and injector nut seal ring.
4. Mount the adapter and assembled injector parts in the
Injector Pressure Holding Test
support bracket (adapter plate not needed). Refer to Fig.
This test determines if the body-to-bushing mating surfaces
in the injector are sealing properly and indicates proper
5. Install the offset clamping head on the clamping post (on
plunger-to-bushing fit.
J 23010 testers without serial numbers, use the upper
detent position and on J 23010 testers numbered 1051 and
1. Clamp the injector properly and purge the air from the
higher, use the lower detent position).
system.
6. Select the (larger) 9/16"-18 threaded coupling nut J
2. Close the Thru-Flow valve, but do not overtighten.
23010-20 and thread it on tubing J 23010-75. Install the
tubing and fitting to adapter J 23010-167.
3. Move lever 2 to the rear, horizontal position.
7. Connect the tubing to tip test adapter J 23010-129 by
4. Operate pump lever I until gage I reads approximately
threading the coupling nut on the tip test adapter.
700 psi.
Installing Adapter and Tube Assembly on Tester J
5. Move lever 4 to the up position.
23010
6. Time the pressure drop between 450 to 250 psi. If the
pressure drop occurs in less than 15 seconds, leakage is
1. Position the adapter and tubing assembly with the solid
excessive.
projecting end located in the hole on the left side of the
support bracket.
Refer to the Trouble Shooting Charts in Section 2.0 if the
fuel injector does not pass any of the preceding tests.
2. Swing the clamping head over the adapter and clamp it
with the oil supply outlet aligned over the open projecting
If the fuel injector passes all of the above tests, proceed
with the Fuel Output Test.
NOTE: Use the fuel injector clamping
Unclamping the Injector
procedure to clamp adapter J 23010-167
in the injector tester.
1. Open the Thru-Flow valve to release pressure in the
system.
Spray Tip Test
2. Move lever 5 down to release the clamping pressure.
1. Move lever 4 down and operate pump lever I with even
3. Swing out the adapter plate and remove the injector
after the nylon seals in the clamping head are free and
2. Note the pressure at which the needle valve opens on
clear of the injector filter caps.
gage 1. The valve should open between 2300 and 3300
psi. The opening and closing action should be sharp and
4. Carefully return lever 5 to the up (horizontal) position.
produce a normal, finely atomized spray pattern.
Needle Valve Tip Test (Using J 23010 Tester and Tip-
If the valve opening pressure is below 2300 psi and/or
atomization is poor, the cause is usually a weak valve
Test Adapter)
spring or a poor needle valve seat.
Assemble injector parts on tip test adapter as follows:
If the valve opening pressure is within 2300-3300 psi,
proceed to check for spray tip leakage as follows:
1. Clamp the flat sides of the tip test adapter J 23010129
firmly in a vise and assemble the cleaned injector parts
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