Ford 9n strange behavior

[Big Red PW]

My Ford 9n is being a pain. It starts on a quarter turn when cold, runs about 10 minutes and starts to miss and dies at 15 minutes. Through the winter I replace the coil, rebuilt the carb, replace the distributor, tune-up kit, ignition switch and resistor and finally the cap, wire and plugs. When it finally dies I no longer have spark. Let it cool completely and it fires right up. Sure seems heat related but I can't find it. Checked the distributor on the bench with a VOM and can't find any shorts. Any suggestions are welcome. I've spent too much money and feel embarrassed I haven't found it. Help please......

 

[sotxbill]

Check coil with volt meter when it quits... do you still have 6 volts to the negative side of the coil with the switch on???? assuming its still a 6 volt... Did the ballast resister go open? can you jumper voltage to the ballast resistor and try to crank it? So you can start to narrow down the problem. Are you sure its no spark????

 

[old]

My Ford 9n is being a pain. It starts on a quarter turn when cold, runs about 10 minutes and starts to miss and dies at 15 minutes. Through the winter I replace the coil, rebuilt the carb, replace the distributor, tune-up kit, ignition switch and resistor and finally the cap, wire and plugs. When it finally dies I no longer have spark. Let it cool completely and it fires right up. Sure seems heat related but I can't find it. Checked the distributor on the bench with a VOM and can't find any shorts. Any suggestions are welcome. I've spent too much money and feel embarrassed I haven't found it. Help please......

Put the old condenser back on and try it if that doesn/t work put the old coil on and try

 

[Big Red PW]

I do have voltage at the coil and I jumpered it out to verify. When it dies and I crank it the ammeter shows pulses so it "looks" like the coil is charging and discharging.
I was just reading that replacement condensors are suspect and can behave this way. I plan to remove it from the circuit and try short-term.

 

[Big Red PW]

Put the old condenser back on and try it if that doesn/t work put the old coil on and try

I've tried the old coil and begaves the sane. I will try the old condensor.

 

[old]

I've tried the old coil and begaves the sane. I will try the old condensor.

The moment it dies carefully grab the coil and see if it is to hot to hold if it is good chance it is bad and now days many new coils are bad from the get go

 

[Big Red PW]

The moment it dies carefully grab the coil and see if it is to hot to hold if it is good chance it is bad and now days many new coils are bad from the get go

Our outdoor temps have been in the 50s and the coil and distributor are all cool to the touch. The liwer engine block is still cool too. Acts like heat but no heat and coil stays cool. Both coil act the same (old and new)

 

[old]

Our outdoor temps have been in the 50s and the coil and distributor are all cool to the touch. The liwer engine block is still cool too. Acts like heat but no heat and coil stays cool. Both coil act the same (old and new)

You might try a hot wire from the battery ignition side to the coil and see if it stays running

 

[Big Red PW]

Good thought.....tried that which also bypasses the resistor......ran the same unfortunately.

 

[Blue Jay]

Try by passing the key switch

 

[Powered By IH]

It's your condenser. Replace it or put the old one back in.

 

[DaveBN]

How much side to side movement do you have for your distributor shaft? Maybe the bushings are worn out. How much gap for your points setting? Are the lobes that open the points worn down too much? Is their a notch where the distributor cap fits onto the body of the distributor and is that assembled correctly. Do the hold downs for the distributor cap snap into place and hold the cap down firmly? Are you sure you have the correct rotor and does it fit snuggly on the shaft?
Lastly, try running it in the dark. You may see where the spark is jumping to instead of going to the pluggs.
Dave

 

[used red MN]

It's your condenser. Replace it or put the old one back in.

I was just reading that replacement condensors are suspect and can behave this way. I plan to remove it from the circuit and try short-term.

I will not run worth a crap without a condenser in the primary ignition circuit. Put in a new one, go to NAPA or some other parts store that has name brand ignition parts like Standard and get a replacement condenser.

 

[Big Red PW]

Conclusión
Yep, the 30 yr old condenser works fine. Apparently the new one was junk.....frustrating, but fixed.

 

[Caryc]

I've heard lots of stories of problems with condensers, even new ones. I've never had a problem with one, of course I've never replaced one.

Is there a way to check a new condenser besides just putting it in a tractor to see if it works right?

 

[a49deere]

you are supposed to be able to check them with meter!

 

[Vac-14]

My Ford 9n is being a pain. It starts on a quarter turn when cold, runs about 10 minutes and starts to miss and dies at 15 minutes. Through the winter I replace the coil, rebuilt the carb, replace the distributor, tune-up kit, ignition switch and resistor and finally the cap, wire and plugs. When it finally dies I no longer have spark. Let it cool completely and it fires right up. Sure seems heat related but I can't find it. Checked the distributor on the bench with a VOM and can't find any shorts. Any suggestions are welcome. I've spent too much money and feel embarrassed I haven't found it. Help please......

I had a similar experience ,i cleaned the battery ground wire where it bolted to the frame , fixed the problem

 

[used red MN]

I had a similar experience ,i cleaned the battery ground wire where it bolted to the frame , fixed the problem

Does the tractor you’re talking about utilize hand crank only? If your starting it with the starter that places a way higher current load on that ground connection than the ignition. Did you maybe do something else at the same time and forgot about that? Not saying your findings weren’t legitimate, just maybe questionable in regards to electrical theory.

 

[Big Red PW]

Interesting thought....I previously installed new battery cables. I cleaned the ground connection and used star washers that improved the contact. The engine starts cold very easy and then would stumble and then die after a few minutes of running. I only changed the condenser and it seems fine.

 

[used red MN]

Interesting thought....I previously installed new battery cables. I cleaned the ground connection and used star washers that improved the contact. The engine starts cold very easy and then would stumble and then die after a few minutes of running. I only changed the condenser and it seems fine.

Big Red, I did a “forum semi no- no” that reply was quoting vac-14. I kind of wonder how often the “miracle battery cable to ground connection cleaning” that is often reported on here as “the fix” really is what fixed the problem? Or was it something else the individual did at the same time but was convinced in their mind they previously checked that other problem X and that couldn’t have been the “actual” fix. Not saying a battery cable connection on an old tractor can’t be problematic. To me if he used the battery cable circuit to crank the high amp starter motor, but then at the same time that circuit couldn’t provide a few amps to operate the engine’s ignition, this seems to me to be questionable hypothesis.