Engine and Controls (cont.)
Trouble, Symptom & Condition
Test or Inspection
Corrective Action
Engine will not start. Starter
will not crank engine
(continued).
g. Internal seizure
If all engine starting components
are good and the starter is
unable to crank the engine,
internal seizure is indicated.
Attempt to hand-crank the
engine, using a socket wrench
with long flex handle on the
crank shaft pulley screw. If the
engine cannot be turned a
complete revolution, remove
engine and disassemble to find
damage and cause.
2.
Engine will not start. Cranking
speed low.
a. Low battery output or faulty
starter.
Check battery and starter.
Recharge, repair, or replace.
b. Loose starting circuit
connections or faulty cables.
Check all connections and
cables. Tighten or replace as
required.
c. Improper lubricating oil
viscosity.
Check oil. See Sect. 2-1, Para.
3, D, (3).
3.
Engine will not start. Cranking
speed normal.
a. No fuel.
Before attempting to find the
cause of “no fuel”, prime the
fuel filters by removing pipe
plug in the cover of each. Fill
each filter with fuel oil. If the
engine will not start after
priming, mechanical pump
trouble is indicated. If the
engine starts and then stops
after a short time, trouble
between the fuel source and
the suction side of the pump is
indicated. Check and/or remedy
as follows (see Fig. 7).
b. Low compression which
may be caused by any of
the following:
Check compression in
accordance with Para. 9, C and
D.
c. Sticking or burned exhaust
valves .
Cylinder head must be removed
and overhauled to correct this
condition.
d. Compression rings worn or
broken.
Check rings in accordance with
Para. 9, E, (1).
e. Cylinder head gasket
leaking.
Check gasket in accordance
with Para. 9, E, (2).
OM-2040 / Operation and Maintenance Manual
90D20 / Generator Sets
Chapter 3-1
February 28/94 Revised
Page 12
Summary of Contents for 6921 Series
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