I know your all going to tell me to chech tha battery.
I charged it all evening and used a booster.
the strange thin is that with or without the booster the engine cranks at the same speed. slow.

I made certain that the terminls on the starter we're tight and clean. I also jumped the solenoid with the same results. slow.

Is it possible that a fuseable link causes this?
Is it possible my starter is shot?
My battery showed 12.5 volts after an evening of charging. After some "slow cranking" it was at 12.4
Like I stated. the booster that usually spins an engine by itself had the same results.
what wlse should I bee looking for?

 

Did you check the battery connection at the starter and the condition of the grounds both at the battery and at the frame?

It's very possible the starter is bad. Next time the starter is cranking slow, whack it with a hammer a few times. Don't worry, you won't hurt it. See if it spins the engine a bit faster. Sure sign that the starter is toast.

Time for a high torque mini starter.

 

I think I'll try the battery out of another car just to make certain.
would a 10:1 engine need a high torq starter? would using the old one or a stocker eventually end in failure?

 

The high torque mini starters are really for their compact size so they stay away from the hot exhaust, and for their gear reduction, which makes them high torque, which means they use less power to start the engine. By all accounts that means they would last longer than a stock size starter. They are easier to install too if you ask me.

For pre-HEI there is an extra wire that needs to be run from the coil, but that info won't be hard to find.

 

I seen some decent priced new Tilton style high torque starters for $78.00 on ebay. Read the whole ad. The vendor is out of Tennessee and stands behind their product.

 

Do not start the car, but turn on your headlights...HI beams, too. If the headlights are well lit, your battery is not the problem; if the lights are dim, get another battery. A "booster" charge is no help to a battery trying to start a car, unless it is a professional, high current model. I'll put 'odds' on the battery.

 

Yeah I suggest that one, the seller is a member here on this forum.

Just make sure the bolt pattern matches your block.

 

Yeah, I'm going to put another in to test..
Do stores test batteries? Do they claim they're all bad to make a sale? hehe

 

get an amp gauge,it'll tell if starter is drawing too many amps indicating bad starter.beats guessing.

 

12.5 isn't enough after an evening of charging. Try a known good battery. Take yours out of the circuit. Jumping a battery that's bad will draw down the good battery amps while cranking.

 

Most major parts stores will test your battery and your starter. You can easily test the starter at home by removing it from the engine and placing on a bench.
1 Get a battery and 3 wires.
2 hook 1 wire to the negative battery terminal and one to the starter ground post
3 connect the 2nd wire from the positive battery terminal to the starters large terminal (the post you disconnected from the battery)
4 connect your 3rd wire to the positive battery terminal.
5 when ready monentarily touch the the 3rd wires other end to the starter post that had the ignition hooked to it.

At this point the starter should spin really fast as long as that 3rd wire is connected. If this works the starter is good and the problem is in the battery or your wiring.

 

the battery starts my wife's hemi durrango. It's either a bad ground (the one from the battery to the frame) or the starter. I'll get her up in the aor to check the frame ground (th ground's right by the dual exhaust I installed a month ago) Any luck it's something as simple as that.

 

Check the ground connections first. That would be my guess as you have charged the batt and saw no improvement. Pull off the cable under the car and clean both ends real good.

Next - Look for a small date code sticker on the side of the battery case. It will look something like "B6" or some other combination of digits. The first digit is the month so a "B" is for "February" and the second digit is the last digit of the year so a "6" is for "2006". If it is older than about 4 years I would have it load tested for free at the car parts store.

I bet on the bad ground connection under the car.

-Mark.

 

All,
FYI.
It was the starter... after tracking down and replacing / tightening all the grounds(not a bad thing anyway)
I finally replaced the starter... with a rebuilt stocker because of the doubt as to if that was the issue....

IT WAS.. IT cranks like a new car.....
tough to diagnose a starter as it seems less likely of the 4 or 5 possible issues....
thanks
to all of you for your help...
timg

 

Has anyone ever dissected one of the stock starters, after they die, to find out what usually causes them to die?

I've been running headers and sidepipes for awhile now and my starter still cranks the engine like new, and it's original.... knock on wood. Hence I'm not a subscriber to this heat soak philosophy.

 

With this simple test your probably right in assuming the ground at the cross member is the source of the problem. A high torque starter is recommended but you my already have one in the car its just your picking up a ground from a weaker source causing the slow turnover.

High torque starters have approximately 3/4 inch distance between the solenoid switch and the field post on the starter normally covered with a copper connector and a longer small bolt. If this is what you have, your already using a HT starter. Stay away from suggested expensive "mini" starters unless you buy two. One in and one ready to go in...The OEM stuff got the car this far, and it did all right. No need for that high dollar imported crap...
.

 

Geesh I like your thinking.. it really makes things clear...

It's a 10:1 street car not a top fuel racer...

timg

 

To all,
I hope no one minds but let me share a little about the theory of a starter motor and some basic battery/starter diagnostics.

To start with conventional starter motors, which is the stock C3 starter, are essentially two opposing magnetic fields. One magnetic field is created by the current flowing throught the field coils in the starter housing and the other is created by the current flowing through the movable armature. The greater the magnetism the greater the opposing force therefore the better the starter operates. To answers Kalway's question the majority of the time the brush to commutator contact has decreased therefore the ability of the amperage to flow through the starter is reduced. That's why DBs tip of "whacking" the starter might cause the starter to work better.

How about the heat issue; several things can cause the starter to work relatively fine when cold but not when hot. One goes back to brush contact; the springs that press against the brushes are like wound choke springs, though not bi-metalic, they can lose tension when hot and therefore the brush contact is decreased. The other one is a short to ground caused by the expansion of the copper causing the insulation to chaffe, therefore creating a shorter path to ground which causes a weaker magnetic field.

Testing: First things first you have to have a good battery, that's what alot of you indicated. We used to test batteries using a carbon pile, voltmeter and ampmeter. The new testers now go much beyond that such as internal load ripple current. Here is a quicky battery test, when cranking the engine the battery voltage should never dip below 9.6V, if so try charging the battery.
As for the starter itself you do need a good Digital Volt-Ohm Meter (DVOM) and an inductive amperage meter. Both of these items are obtainable anywhere and for a DIY user you do not need an overly expensive one that a professional technician would require. You hook the DVOM across the battery and the ampmeter to either battery cable; crank the engine. Real world values are voltage between 10.5V to 11.5V and amperage between 175A to 250A. If the voltage is low start with the battery. If the voltage is low and the amps are high it is likely the starter is shorted or the armature is dragging. If the voltage is normal and the amps are low start eliminating the connections.

I call this the Voltage Drop test VD for short. Take one of the test leads off of the battery; example remove the negative test lead and move it to the large terminal on the starter. You are now testing the voltage lost between the positive battery terminal and the starter terminal; while cranking the engine .5V or less is acceptable.
Now move the lead from the positive side of the battery to the negative and move the lead from the starter terminal to one of the starter mounting bolts and repeat the cranking test; again .5V or less is acceptable.

I hope this helps everyone the next time you run into starting issues.

BTW much of the electrical system of our automobiles operates on the basics of magnetism and proper current flow.

norm