Kirk...
Is this a cranking problem or a "firing" problem? IOW, it's cranking over
normally
but not firing (except once in a while) or
it's NOT cranking over normally but fires
once in a while.
Everything associated with the starting system will get hot when you crank a
motor
over and most assuredly so if you crank
"excessivley".
With an automotive engine, if it's not turning over fast enough, it may not
start
though it may fire intermittently, usually
weakly and this can be a weak battery or
high resistance in the starter, solenoid,
or attendant wiring.
A battery can show over 12 volts "statically"
but flunk under a "dynamic" load (test)
due to fault within, as in a bad or dead cell.
Spark to the plug won't jump the gap unless the plug's ground electrode is
grounded against something...like the block
fr'instance!! Usually the plug is situated in
the block, right??? There you go!!
If the motor was turning over normally at
a normal rate and it's not firing than the
problem can be an ignition or fuel problem.
If the plugs are wet and smell like gasoline
when you pull them, the problem is probably ignition seeing as fuel is
definitely getting to the plug.
If the plug is dry, then it's the "other way"
and ignition systems components are due
for a check.
And remember...
A bad starting system (bad battery, etc.) can hold an engine back from
continued firing after initally doing so. The
idea is the starter spins the engine fast
enough for starting and disengages "cleanly upon the motor's
initial firing, allowing the motor to accelerate to higher rpm.
If the cranking power/speed is
low (batteries must be checked "statically"
as well as "dynamically" or under load to
be found fully satisfactory), all bets are off
regarding the engine's continued firing
after a cylinder initially fires as a "clean"
dis-connect may not occur and attendant
starter "drag" actually SLOWS rotation of the engine.
Now if you continue to crank the motor without suitable rest periods for
starting
system components to cool, you'll "fry"
whatever is the weakest link in your
starting system. Because once the system
becomes hot, the resistance of all goes up
as does thermal increase RATE with repeated attempts.
Cap'n Bob
Basic Frog
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