TM 5-3895-383-24
1.
Air in fuel system:
With air in the fuel system the engine will normally
be difficult to start, run rough and release a large
amount of white smoke. If air is in the system, it will
generally get in on the suction side of the fuel
transfer
pump.
Check
for
leakage
at
the
connections between the fuel tank and the fuel
transfer pump. If leaks are found, tighten the
connections or replace the lines. If there are no
visual leaks, remove the fuel supply line from the
tank and connect it to an outside fuel supply. If this
corrects the problem, the suction line (standpipe)
inside the fuel tank has a leak. If this does not
correct the problem, install a sight tube in the fuel
return line and check the injectors to verify that they
are properly seated.
This can be accomplished by moving each injector
(one at a time) to the "FUEL ON" position
momentarily and checking the sight tube for any
increase in air bubbles. Push on the rack bar on
the exhaust manifold side of the injector to move
the injector to the "FUEL ON" position. If an
increase in air is found, then remove that injector.
Check the tip seal (O-ring) and replace if R is
defective. Inspect the injector sleeve for a smooth
sealing surface for the injector to seat on. If any
defects are noted, the sleeve can be reamed or it
can be replaced if necessary.
The temperature of an exhaust manifold pod can be
an indication of a cylinder that has air being
delivered to it. Check the exhaust manifold
temperatures and compare the results. A lower
than normal cylinder temperature indicates that the
cylinder may be receiving air from the injector.
The color of the exhaust smoke can also indicate
which cylinder has a combustion leak. Move each
injector (one at a time) to the "FUEL ON" position
momentarily while checking the color of the exhaust
smoke. The cylinder that has air will produce
smoke that is gray or white in color.
2.
Low quality fuel:
Remove the fuel from the fuel tank. Install new fuel
filter. Put a good grade of clean fuel in the fuel
tank.
3.
Incorrect fuel injection timing dimension:
Check and make necessary adjustments as per
Testing and Adjusting Section of the Service
Manual.
4.
Improper injector synchronization:
Improper injector synchronization will cause more fuel
to be delivered to one cylinder. This will cause a
combustion "knock". The over fueling cylinder(s) can
be determined by moving each injector (one at a time)
to the "FUEL ON" position and listening for a
combustion "knock". Check and make necessary
adjustments as per Testing and Adjusting Section of
the Service Manual.
5.
Defect in fuel injector(s):
Use the 1U6661 Pop (injector) Tester to check the
injectors for proper operation. Refer to Special
Instruction, SEHS8867 for additional information.
6.
Mechanical problem:
Find and correct the problem. The problem may be
incorrect valve adjustment, sticking valve, or other
internal problem.
Problem 13: Valve Train Noise
Probable Cause(s):
Too Much Valve Lash
Damage To Valve Springs, Locks, Push Tube Or
Worn Valve Lifter
Not Enough Lubrication
Damage To Valves
Damage To Camshaft
1.
Too much valve lash:
Check and make necessary adjustments as per
Testing and Adjusting Section of the Service
Manual.
2.
Damage to valve springs, locks, push tube, or broken or
worn valve lifter:
Install new parts where necessary. Broken locks
can cause the valve to get into the cylinder. This
will cause much damage.
3.
Not enough lubrication:
Check lubrication in valve compartment. There
must be a strong flow of oil at engine high rpm, but
only a small flow of oil at low rpm. Oil passages
must be clean, especially those that send oil to the
cylinder head.
4.
Damage to valves:
Make a replacement of the valves and make an
adjustment as necessary.
5.
Damage to camshaft:
Make a replacement of parts with damage. Clean
engine thoroughly.
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