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PART 8-1-
GENERAL ENGINE SERVICE
8-3
DIAGNOSIS GUIDI
ENGINE WILL
NOT CRANK
ENGINE CRANKS
NORMALLY, IUT WILL
NOT START
The cause of this trouble is usually
in the starting system (Group 14).
If the starting system is not at
fault, check for a hydrostatic lock
or a seized engine as follows:
Remove the spark plugs; then
attempt to crank the engine with the
Check the fuel supply. If there is
sufficient fuel in the tank and the
proper starting procedure is used, the
cause of the trouble probably lies in
either the ignition or the fuel system.
To determine which system is at
fault~
perform the following
test:
Dtsconnect a spark plug
wire.
Check the spark intensity at the end
of the wire by installing a terminal
adapter in the end of the
wire.
Then
~old
the adapter approximately
*
mch from the exhaust manifold and
crank
~he
engine.
IF THERE IS
NO
SPARK
OR A WEAK SPARK
AT
THE SPARK PLUGS
The cause of the trouble is in the
ignition system.
Disconnect the brown lead (I
terminal) and the red and blue
lead (s terminal) at the starter
relay. Install an auxiliary starter
switch between the battery and s
terminals of the starter relay.
To determine if the cause of the
trouble is in the primary or the
secondary circuit, remove the coil
h~gh
.tension lead from the top of the
dtstnbutor, and hold it approxi-
mately
3
/
16
inch from the cylinder
head. With the ignition on, crank
the engine and check for a spark.
If the spark at the coil high tension
lead is good, the cause of the trouble
is probably in the distributor cap,
rotor or spark plug
wires.
If there is no spark or a weak
spark at the coil high tension lead,
~he
cause
_
of the trouble is probably
m the pnmary circuit, coil to dis-
tributor high tension lead, or the coil.
IF THERE IS
A
GOOD SPARK
AT
THE SPARK
PLUGS
Check the spark
plugs.
If the spark
plugs are not at fault, check the
following
items:
MANUAL CHOKE
Check the choke linkage for bind-
ing or
damage.
Make certain the
choke plate closes when the choke
knob on the instrument panel is
pulled out and that the plate opens
when the knob is pushed
in.
~ta~ter.
If the engine cranks, it
mdicat~s
that water is leaking into
the cylmders. Remove the cylinder
head(s) and inspect the gasket(s)
and/
or head(s) for cracks. Examine
the cylinder block for cracks.
AUTOMATIC CHOKE
Check the position of the choke
plate. If the engine is hot, the plate
should be open. If the plate is not
open, the engine will load up due to
the excessively rich mixture and will
not
start.
If the engine is cold, the
plate should .be closed. If the plate
1s not operatmg properly, check the
following items:
The choke plate and linkage for
binding.
The fast idle cam linkage for
binding.
. Thermostatic spring housing ad-
JUStment.
FUEL SUPPLY AT THE
CARBURETTOR
Work the throttle by hand several
times. Each time the throttle is
actuated, fuel should spurt from the
accelerating pump discharge port
(6-cylinder)
or nozzles (V-8).
If fuel is discharged by the accel-
erating pump, the engine is probably
flooded, or there is water in the fuel
system, or an engine mechanical item
is at fault.
If fuel is not discharged by the
accelerating pump, disconnect the
carburettor fuel inlet line at the
carburettor. Use a suitable container
to catch the fuel. Crank the engine
to see. if fuel is reaching the car-
burettor.
If fuel is not reaching the car-
burettor, check:
The fuel filter.
The fuel pump.
The carburettor fuel inlet line for
obstructions.
The fuel pump flexible inlet line
for a collapsed condition.
The fuel tank line for obstructions.
For fuel tank vent restriction.
If fuel is reaching the carburettor
check:
The fuel inlet system including the
fuel inlet needle and seat assembly
and the float assembly.
ENGINE
Mechanical failure in camshaft
drive.
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