On Fri, 29 Aug 1997 23:03:39 -0400 (EDT) RatiganJ@aol.com writes:
>..... The 1500 engine has been completely rebuilt ..... turned the key,
pulled the starter knob.....and.....the starter would barely turn the
engine over. ..... Is this a typical situation?
Yes and no. Uh ..... that is, it sometimes happens, but it shouldn't be
that way.
>Is the engine so tight that the starter is barely able to turn it over
at all.
Same answer: Maybe, but it shouldn't be that tight. Who assembled the
engine? Do you know how tight it is? If you can turn the engine by hand
with no more than 20 lb-ft of torque, the starter should spin it over
just fine, and it should start right up.
Suppose you don't know how much torque it takes to turn the engine? Do
this: Put it in forth gear, brake off, and roll the car forwards and
backwards vigorously by hand. If the engine turns a bit, so you can see
the fan blade move, it is not too tight. Or, you can get underneath and
put a big wrench on the crank nut and try to turn it by hand. You should
be able to turn it with one hand with a 10" or 12" wrench.
If the engine is really tight, you have a BIG problem. In that case,
stop here and call back immediately. For now let's suppose the engine is
not too tight.
>Should I pull the car and pop the clutch to start it?
NO !!! If the engine is too tight, forcing it to turn could cause
serious damage to the bearings and crankshaft. First you have to be sure
the engine is not too tight. If the engine is not too tight, you still
have to fix its' started problem anyway, and if you fix it, you won't
have to tow it.
>Or should I get the starter rebuilt?
If you can turn the engine by hand, or by rocking the car, then you have
a simple (read "less expensive") starter problem. Then proceed with the
following.
You need an amp meter for this. I have a little round amp gauge that you
just lay against the wire. It works by induction. It was cheap, and I'd
be surprised if it was more accurate than +/- 20%, but it works good for
this test. If the starter motor draws more than about 300 amps, and
still doesn't spin the engine, the starter motor has internal problems.
Could be shorted windings. Could also be a short where the cable
connection stud goes through the end plate.
If it draws less than 100 amps, the battery could be bad, or the large
battery and starter cables could have bad connections somewhere, or the
starter could be bad internally.
First, have the battery (or batteries) tested, or substitute a known good
battery. For this you can use jumper cables from another car with a good
battery. + to + and - to -.
Second, be sure the engine ground cable is in place. This is a short
piece of cable between the engine and the chassis. Original location is
across the left engine mount, but it could be between the bell housing
and the bulkhead, or between the cylinder head and the heater shelf. If
it isn't there, you won't have a good enough ground return to the battery
to draw enough current. If this is the case, installing a jumper cable
(or two) from the engine block to the frame should cure the problem.
Third, the starter could have worn out brushes or burned commutator, or a
broken winding (or windings). If you got this far, it's time for a
voltage check at the starter motor. Connect one lead of a volt meter to
the engine block or starter motor housing for a good ground reference.
Connect the other lead of the volt meter directly to the exposed end of
the copper stud on the starter motor -- not to the cable or the nut, but
right on the threads or on the end of the threaded stud. Have an
assistant operate the starter switch while you read the volt meter. If
the voltage when cranking is less than 8 volts, the battery is weak, or
you have bad cable connections somewhere. If the reading is 9 volts or
more, and still not cranking properly, the starter would be bad.
It is best if you can get both a current reading and a voltage reading.
a.) High current and High voltage means lots of electrical power is
going somewhere. If the engine isn't too tight, and it's not spinning,
then the current is being dissipated as heat (lots of heat) inside of the
bad starter motor.
b.) If the voltage is low and the current is high, it's a dead
short inside the starter motor.
c.) If the voltage is high and the current is low, there's a bad
connection inside of the starter motor.
d.) If the voltage and current are both low, you have a bad
battery, or loose cables, or possibly a bad starter switch. Usa a known
good battery and jumper cables. Putting power directly to the starter
motor should make it crank well, otherwise the starter motor is bad.
>..... Also, should I choke the engine, pump the gas pedal, or what?
Any thoughts or suggestions would be greatly appreciated.
Best way to start a cold engine with SU carbs (assuming it cranks over
properly):
a.) Turn key on and let the electric fuel pump run until it slows
down or stops, indicating that the float chambers are full.
b.) Pull choke out all the way.
c.) Depress throttle pedal about 1/4", just far enough to have
enough air to keep running when it starts, but still mostly closed so it
draws a little vacuum on the fuel jet.
d.) Crank engine until it starts. Should be a few seconds in mild
weather, maybe as much as 10 seconds in very cold weather, or with a new
engine!
SU carbs have no accelerator pump, so stomping on the pedal does nothing.
Without an accelerator pump, it takes a while to get enough fuel into
the cylinders. Reason it needs a lot of extra fuel when it's cold? Only
the fuel vapor will burn, not the liquid. When it's very cold the liquid
fuel evaporates more slowly, so less vapor.
Keep in touch,
Barney Gaylord
1958 MGA with an attitude
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