I hit the key, and she cranks the starter a bit slow for a couple of turns then dies out. Acts exactly like a low battery.
Battery is new (1 month old). The car has not been driven since the new battery was put in, but it was started several times, and allowed to run a while. At first it cranked over just fine as you would expect with a brand new battery.
Last week, the slow crank and die started. Charged battery, same thing. Brought battery to Interstate, they tested it and said it was fine. Cleaned all major connections - battery post connections, trans ground strap, battery ground to body, battery cable connection at starter. No improvement.
I do have a starter relay installed, it has been there for many years.
Help Please! I stumped.

Have you checked to see if your alternator is charging when the car is running?

Check your tranny ground strap ...


EDIT: Saw that you did, alternator check is next.

I charged the battery fully. No difference. Or are you saying that an alternator issue can cause a voltage drain?

You still have bad connections somewhere.

Try running a ground wire from the battery directly to the case of the starter. A nice FAT one.

Does that help? Then something in the regular ground path is not right.

You could also have a corroded battery (+) cable.

--DD

Might wanna have an amp draw test done on the car. Could be a HUGE draw within the starter. I've also seen starters shorted internally that sucked a battery down in a matter of minutes.

The Cap'n

OK - I used heavy duty jumper cables. Body of starter to battery ground post. No difference. Battery positive to positive log on the solenoid. No difference.
Voltmeter on the + and - terminals - 12.53 volts. Turn key and crank starter - goes down to 10.3 volts. Is that normal, or bad battery?

Thanks again. This is driving me nuts. Snow is finally melting and I want to actually drive it this year!

Starter

It lasted 40 years, be happy.

Jumper cables won't do it. You need a large wire fastened securely. remove and clean the starter connections. Then remove starter an take it to a local starter repair ship

It seems like something binding or startermotor is dying , just for the hell of it , take the 4 spark plugs out and see if it rotates any differently ,also maybe by pass the key
with a jumper wire at the starter just to see if it rotates any differently . The starter on
my car was acting up awhile back , I took the starter out and half apart to clean & lubricate , I also installed a relay under the dash , made a big difference , Bill D.

I did troubleshooting on my car being hard to start until one day the starter stopped working all together. I was amazed how quickly it turned over once I replaced the starter.

Sounds like the starter may be going bad. The brushes in the starter are carbon and the commutator eats the brushes over the years. The resulting dust acts like a resistor and less voltage/current gets to the motor part of the starter. Sometimes disassembling and blowing out with air will help. If it is too oily/greasy, them more is needed to clean the dust out.
Tom

Jack up the oil fill plug on the top of the motor and run a new car under it...

Or, find out what that starter is drawing. Assuming your ground is good and the battery is charged, you have a problem in the circuit to the starter or the starter...

That is difficult to do as most of the current meters us "non-professional" electricians have cannot measure above ~10 Amps.

I pulled the starter.
NAPA said they had a Bosch SR17x in stock. Went to pick it up, and it is the SR15x. All the books say it is a compatible replacement, but it is a LOT smaller.
All other local places have rebuild versions of the Sr15x too.
Anybody know anything about them? Will it work? Is is weaker?

I bought the high torque starter on ebay.

Seems to work good, but I've only started the car ~50 times since i installed it.
They are much smaller than stock

The books are wrong.

--DD

Put in new starter, and it cranks faster than I can remember in a LOOOONG time.
WOW, what a difference. I've never seen a starter fail this way. It has always been either nothing from the starter at all, or really bad noises, but not slow crank.
I wonder if a lot of the hot start issues are really starters beginning to go out, so they need extra power to spin?
Thanks everyone for the advice.
Now I just need to get the heat exchangers connected to the warm air pipes, hook up the flapper vales to the new cables, and adjust the driver window so it actually seals to the top. I'm sure I'll be begging for help on that one....