Starting problems with Ford 8N

[Steve1970]

Hello together

I have the following problem with my Ford 8N. When I start the car, I have to use the starter for ages until it starts. It usually drains my 6 volt battery at least once. When I checked it I found a weak spark and now I installed a new ignition coil. The spark is now much better, whereupon he then also started well. After a short drive, of about 2 kilometers and a standstill of 1 hour, I could not start it again. When checking the spark plug, I again had only a weak spark. The spark plug itself looked good from the color. When I tried to start it again, I noticed that it always ignited as soon as I stopped using the starter. Like a re-ignition. My theory now is that the starter is causing the battery voltage to drop to the point where there is not enough for a proper spark. Can you guys confirm my theory or do you have any other tips? Please excuse my bad English. But in Switzerland we only speak German, French and Italian ;-)

Have a nice day
Steve

 

[Tim PloughNman Daley]

8N TRACTOR OR A CAR??? Which is it? Are trying to jump start your 8N with your car? If an 8N, is it a front mount or a side mount model? Is it 6V/POS GRN or have you
done a 12V switcheroo job? Don't assume just because your battery is 6V (or 12V) the system is wired correctly. Verification required. GEN or ALT must have a belt
tensioner otherwise you will never charge the battery. Either way, is it wired correctly for that system? At start up, when you turn ign key ON and press the Neutral
Safety Start Pushbutton shifter lever, what happens? Click Click Click? Your battery is dead. Take battery to a reliable shop and get it tested on their machine. they
will test you starter motor as well so you you can won't have to guess any of your 'THEORIES'. A battery left idle with no float charger attached will drain battery
after a week or longer. It ain't your coil, or starter, most likely mucked up wiring. When it ran,waht did your AMMETER show? How did you test it? Stop replacing
parts willy nilly without proper root cause problem solving methods. Perform a true spark test at first sign of trouble. Test battery, coil, GEN, VR, and Starter at
your shop. Maybe this will help you with your wiring - both 6V and 12V shown as you don't specify what you are wired as.

<IMG SRC=https://i.imgur.com/XPx5xXEl.jpg>​

FORD 8N, 6V/POS GRN SYSTEM, FRONT & SIDE MOUNT DISTRIBUTORS WIRING SHOWN:

FORD 8N, 12V NEG/GRN CONVERSION:

*NOTEICTOGRAMS COURTESY OF JMOR.

Tim Daley (MI)

 

[Bruce (VA)]

My theory now is that the starter is causing the battery voltage to drop to the point where there is not enough for a proper spark.

Excellent diagnoses! That is exactly what is happening.

Normally, the cause is a weak battery or a dragging starter. Meaning he starter is drawing too much current and not leaving enough for the ignition.

Check your battery. 6.35 volts is fully charged. Each cell should be 1.265 specific gravity.

Hook your meter in line to your starter. If it's drawing 4 volts or less when you press the starter button, your starter is dragging.
75 Tips

 

[Steve1970]

Good day together

Bruce, thanks for your assessment. Now I also read that the Ford 8N needs about 60 amps starter current when the engine is cold and up to 150 amps when warm. I'll check those currents with my clamp ammeter and also measure how the voltage behaves. I will report back.

Have a nice day

Steve

 

[Bruce (VA)]

Yes, current draw is a more accurate measurement than a voltage drop test, but not everyone has a clamp on meter!

Bitte melden Sie sich erneut
75 Tips

 

[Nyquil Junkie]

When I start the car, I have to use the starter for ages until it starts.

With most all engines, if it doesn't start within 5 revolutions or less, there is something wrong... cranking it until the battery is dead is kinda pointless.

 

[Steve1970]

Your contribution is not very helpful. Definitely, the engine is in order or completely overhauled. I have written that it runs. Everything points either to a too large current consumption of the starter and thus a voltage drop of the battery, or the battery no longer brings the required
power. I have now ordered a battery tester with which I can simulate 100 amps starter current and thus test the capacity of the battery.

I will report.
Best regards, Steve

 

[Jim L WA]

(quoted from post at 07:23:51 05/17/23) Your contribution is not very helpful. Definitely, the engine is in order or completely overhauled. I have written that it runs. Everything points either to a too large current consumption of the starter and thus a voltage drop of the battery, or the battery no longer brings the required
power. I have now ordered a battery tester with which I can simulate 100 amps starter current and thus test the capacity of the battery.

I will report.
Best regards, Steve

Hello Steve1970. Your English is just fine. You seem to be on the right track with your problem However in you original post you asked for tips. Nyquil Junkie was offering one which I think was a good tip. Cranking the engine until the battery dies shortens the life of the battery.

 

[Nyquil Junkie]

Your contribution is not very helpful.

I though it was. You cranked the battery until it was dead trying to get it to start. I pointed out that, all things being equal, if it takes more than 5 rotations for it to start, then there is something wrong somewhere.... meaning stop cranking the life out of the battery, and start looking for a reason it won't pop off.

Granted, old engines with low compression or cruddy fuel or something might start fine after cranking it a while.

My point was... stop cranking, and start looking for a reason it won't start. You did just that and kudos on your diagnosis.

But, you did crank the life out of the battery before you stopped to figure out why it wouldnt start normally...if I read you right, you did this repeatedly.

My helpful advice is.... don't crank it until the battery is dead, if it doesn't at least try to start after 5 turns, stop and figure out why.

Definitely, the engine is in order or completely overhauled. I have written that it runs.

Once you crank it so long it kills the battery it runs.

I'm not being an a-hole, I simply offered a small bit of advice.... to you or whoever reads this later...

Its suppose to start quickly and easy. if it doesn't, save your battery and figure out why it isn't starting quick and easy.

 

[Steve1970]

Hello

Thank you very much for your feedback. In no way did I mean to offend anyone. I apologize if it came across that way. I really appreciate any advice you may have. I forgot to say that when I push it to
start, that is without starting, that it then starts immediately. So my guess is that the battery still has sufficient open circuit voltage, but the capacity is no longer sufficient. But just on the off chance
to buy a new one for 280 dollars, was not yet an option for me. I can still measure the resistance of the winding of the starter and calculate how high the current consumption is. This would give an
indication if the starter is the problem.
Best regards
Steve

 

[Nyquil Junkie]

But just on the off chance
to buy a new one for 280 dollars, was not yet an option for me.

At 280 bucks for a battery, I'd put a velvet pillow under it and lock the barn door. :lol:

That price tag should remind ya not to crank it to death.

No offense taken steve...its all good.

 

[JMOR]

If discussed, I missed it, but another thing that can appear as low voltage to ignition during cranking, ,is light gauge battery cables and/or bad cable connections...corrosion, paint, rust?

 

[Hobo,NC]

(quoted from post at 20:23:51 05/17/23) Your contribution is not very helpful. Definitely, the engine is in order or completely overhauled. I have written that it runs. Everything points either to a too large current consumption of the starter and thus a voltage drop of the battery, or the battery no longer brings the required
power. I have now ordered a battery tester with which I can simulate 100 amps starter current and thus test the capacity of the battery.

I will report.
Best regards, Steve

You just pizz your money away on a whippy battery tester. : (, its built into your tractor.

The other issue is you have not gave enoufh info and your helpers have not asked the right questions. When this gets to page 5/6 maybe the right questions will come about

 

[Steve1970]

Typically Swiss, instead of lead plates we use gold plates.

 

[Eman85]

Do you own a voltmeter? What is the battery voltage? What does it read with the tractor running?