No Spark on 1949 Ford 8N

[ultrarunner]

Every time I have an engine fire right up and then die a few minutes later it was a problem with the fuel vent or the flow to the carburetor was so minute it couldn't replenish fast enough.

Both happen with old Model A Fords...

 

[Bartman1959]

I've had the battery charger on it on slow charge for a couple of days, just in case. I just went out to remove the charger and decided to "give it a try." It fired right up, ran for less than a minute and died. I tried a few more times but it didn't even attempt a restart. I didn't have time to really do anything with it today, so I turned off the key and the fuel and left it for now. I'm at a total loss here.

 

[Oldpath05]

Is this a 6 volt or 12 volt system? So if power/juice is going to the coil, the points are good and set, the condenser is next. Now if I remember sort of right, with the coil being good, I use to be able to rotate the distributer as if adjusting the timing, with rotor button pointing to a plug wire inside the distributer cap, the same plug wire on the sparkplug taken out and leaning/grounding on motor block, than with key on I good rotate the distributor back and forth by hand, that would open and close the points and a spark would jump/arc on the spark plug electrode. That told me that the points was good and set right, the coil was good, the condenser was good, the rotor button was good, cap, wire and plug was good................ Then I would move on to firing order, fuel and learning a few more new words.

 

[Bartman1959]

Is this a 6 volt or 12 volt system? So if power/juice is going to the coil, the points are good and set, the condenser is next. Now if I remember sort of right, with the coil being good, I use to be able to rotate the distributer as if adjusting the timing, with rotor button pointing to a plug wire inside the distributer cap, the same plug wire on the sparkplug taken out and leaning/grounding on motor block, than with key on I good rotate the distributor back and forth by hand, that would open and close the points and a spark would jump/arc on the spark plug electrode. That told me that the points was good and set right, the coil was good, the condenser was good, the rotor button was good, cap, wire and plug was good................ Then I would move on to firing order, fuel and learning a few more new words.

This is a front mounted distributor, so there is no turning it back and forth, it has to be removed to set the timing. I have set the timing using the manual.

 

[Soundguy]

a 1949 8n is a front mount distribuitor.. and points gap at .015

SIDE MOUNT distribuitor 8n's gap at .025


I'n frankly amazed you could get a front mount to gap at .025...

 

[Bartman1959]

a 1949 8n is a front mount distribuitor.. and points gap at .015

SIDE MOUNT distribuitor 8n's gap at .025


I'n frankly amazed you could get a front mount to gap at .025...

Believe me, it wasn't easy. I couldn't figure out why they were so far off from when I installed them at the start of summer. I'll reset them today to .015. I have guys telling me they think my problem is the coil or condenser, what do you think?

 

[Soundguy]

set your points first, then start from there.

I have seen a small handfull of condensers fail in my lifetime... I usually DO NOT suspect them. Generally a cap dies open, and you get pitted points.. very rarely they die shorted, and you get no spark at all, period, because the points are shorted. Even more rare is a time based thermal short where the cap works until warm, then shorts.. on that one.. you have spark, then it goes away and you have shorted points... thus.. caps' rarely are the cause of the problem.

Round can coils are pretty tough.. but the front square coils are just above the level of junk these days.

If you have a front coil, on 6v, and have the OEM resistor, it's fairly stable. If it is on 12v, and you have the 6v coil, you need the oem resistor, plus extra resistance.. usually .5-1 ohm... your target primary resistance is 3 - 3.5 ohms for 12v... and about 1-1.5 ohms for 6v. there are some 12v front mount coils on the market that are in the 2-2.5 ohm range. the 2 ohm ones tend to work fine with the oem resistor on 12v. the 2.5 ohm ones are usually ok, under ideal circumstances with good clean connections.. but under less than ideal conditions and rusty connections.. you can get weak spark.

 

[Bartman1959]

I will start with setting the points in a couple of hours. This is a 12v system. How do you check the ohms on the front mounted coil?

 

[Soundguy]

with an ohm meter, of course.

 

[Bartman1959]

Hahaha, of course. Am I checking the hot wire going into the coil?