Service manual
GLOW
PLUGS
DESCRIPTION
The glow plugs are wired through the preheat solenoid.
When
PREHEAT is pressed at the control panel this solenoid
should
"click" on and the glow plug should begin to get hot.
INSPECTION
To inspect the plug, remove the electrical terminal connec-
tions, then unscrew
or
unclamp each plug from the cylinder
head. Thoroughly clean each plug's tip and threads with a
soft brush and cleaning solution to remove all the carbon and
oil deposits. While cleaning, examine the tip for wear and
bum
erosion;
if
it has eroded too much, replace the plug.
TESTING
An accurate way to test glow plugs is with an ohmmeter.
Touch one prod to the glow plug's wire connection, and
the other to the body
of
the glow plug, as shown. A good
glow plug will have a
0.3 to 0.4
Ohm
resistance. This
method can
be used with the plug in
or
out
of
the engine.
You can also use an ammeter to test the power drain
(8 to 9 amps
per
plug).
A
WARNING:
These
glow
plugs
will
become
very
hot
to
the
touch.
Be
careful
not
to
burn
your
fingers
when
testing
the
plugs.
_GLOW
PLUG
FUEL
LIFT
PUMP
Periodically check the fuel connections
to
and out
of
the
pump
and make sure that
no
leakage
is
present and that the fittings
are
tight and secure. The DC ground connection at one
of
the
pump's mounting bolts should be clean and well secured
by
the mounting bolt to ensure proper pump operation.
When energized thru the preheat circuit, the fuel
lift pump will
purge air from
the
fuel system and provide a continuous
flow
of fuel
as
the engine
is
nmning.
INLET
FUEL
FILTER
To
ensure clean fuel into the fuel lift pump, there is a small
in-line fuel
filt~r
connected
to
the fuel lift pump elbow. This
filter shoufd be replaced every 200 hours
of
operation-.
30
Re-install the plugs in the engine and test them again. The
plugs should get very hot (at the terminal end) within
10 to
15
seconds.
If
the plugs
don't
heat up quickly, check for a
short circuit.
When
reinstalling the glow plugs, use anti-seize
compound on the threads.
Glow
Plug
Tightening
Torque
7
-11
lb-fl
(1.0
-1.5
kg-m)
A
WARNING:
Do
not
keep
a
glow
plug
on
for
more
than
30
seconds.
TERMINAL
END
GLOWPWG
THE
OHMMETER
TEST
TIP