ford 8n will not fire

[catfishonly]

Hi all im new to tractorbynet form.I have a ford 8n front mount dist. i put new coil points and condenser and rotor button and cap on three times still no fire. I know i cant have 3 bad coils and points from different places could any of you help me and tell me what im doing wrong

 

[504piper]

points should be set a .020 . make shure the points will open and close if they don't close no fire. also do you have good coil and plug wires? has this tractor ran lately?

 

[lhfarm]

Hi all im new to tractorbynet form.I have a ford 8n front mount dist. i put new coil points and condenser and rotor button and cap on three times still no fire. I know i cant have 3 bad coils and points from different places could any of you help me and tell me what im doing wrong

Welcome to TBN! Lots of 8N owners (and former owners like me) here, so I'm sure you will get the help you need. You may want to use the search function to look for answers too. More details about what you have done and how the tractor was running prior to the no start would be helpful.

I'm assuming the battery is good and the engine will crank, but not fire. Also assume you pulled a plug wire and got no spark to the block while cranking. Perhaps I should have just asked how you know you didn't have spark.

The good news is that the 8N ignition is pretty simple. Make sure you have power to the coil and to the points. With the ignition on and the points closed, use a screwdriver to open the points. You should see a good spark.

If you have power to the distributor and the points are opening/closing (crank the engine with the cap removed) then it has to be bad plug/coil wires. Have you changed those?

 

[catfishonly]

I tested coil wire with test light and i tested points with test light i have power going to both of them and when points close like they do i have none.But when i take cap off to see if points are sparking i get no spark. and secondary of coil is good also just not getting spark at points. One other thing tractor was running good i done a restaration on it put every thing back together now haveing this problem.

 

[KYErik]

When the points close, the electricity goes to ground so the test light will go out- this is normal.

Can you get a spark from the coil wire when you open the points with a screw driver with the ignition switch on?

 

[Jerry/MT]

Hi all im new to tractorbynet form.I have a ford 8n front mount dist. i put new coil points and condenser and rotor button and cap on three times still no fire. I know i cant have 3 bad coils and points from different places could any of you help me and tell me what im doing wrong

Points should be set to 0.015". Make sure that ballast resistor has continuity and that copper strip is not grounded or broken.

 

[Garybake]

Simple oversight I have done is wire cap firing order rotation wrong because of thinking past the problem.
Gary

 

[J_J]

catfishonly,

With the IGN on, and the HV coil wire close to ground, and points open, put screw driver into the points and remove, and you should see a spark.

When you ground the points, you complete the path for current to flow and high voltage builds up and when you remove the ground, the coil dumps the high voltage through the high voltage wire , or a plug if connected.

 

[catfishonly]

i get fire down to the points after a crank or two i lose spark and will not spark again every thing stays hot just no spark at pionts and points are gaped at 0.15 and like it is supposed to when points are grounded i have no power with test light and when points are open i have power to test light just no spark at points

 

[RickB]

i get fire down to the points after a crank or two i lose spark and will not spark again every thing stays hot just no spark at pionts and points are gaped at 0.15 and like it is supposed to when points are grounded i have no power with test light and when points are open i have power to test light just no spark at points

Bypass the key switch. When you prove it is faulty, replace it.

 

[KYErik]

I'm sorry, but I don't understand your symptom of "no spark at points".

Are you looking for a spark between the breaker points when cranking the engine with the distributor cap off?

Or are you looking for a spark from the end of the coil wire going to any ground (engine,frame etc.)?

Your test light results seem perfectly normal.

You won't always see a spark between the points when they open while the engine is cranking.

Crank the engine until the points are open. Leave the ignition on and place the blade of a screwdriver between the points while you hold the high tension coil wire (the end that normally plugs into the center of the distributor) about 1/4 inch from the engine block. When you pull the screwdriver away from the points, do you see a spark between the end of the coil wire and the engine block?

 

[Sutol]

Bypass the key switch. When you prove it is faulty, replace it.

What he said.....common fault

 

[whodat526]

What he said.....common fault

also by pass the resistor and then

 

[whitetiger]

i get fire down to the points after a crank or two i lose spark and will not spark again every thing stays hot just no spark at pionts and points are gaped at 0.15 and like it is supposed to when points are grounded i have no power with test light and when points are open i have power to test light just no spark at points

Its probably just a typo but point gap should be .015 instead of 0.15
Just checking.

 

[lhfarm]

i get fire down to the points after a crank or two i lose spark and will not spark again every thing stays hot just no spark at pionts and points are gaped at 0.15 and like it is supposed to when points are grounded i have no power with test light and when points are open i have power to test light just no spark at points

This does sound like it might be loosing 6V to the coil if you aren't getting spark after a crank or two. Could be a bad switch or a bad connection. I would check the wiring to make sure you don't have a loose connection, or a pinched or cut wire that is failing when the engine is cranking. Did you try bypassing the switch as suggested? That would eliminate one fault point.

If that doesn't solve the problem and the tractor was running prior to your restoration, I would replace the new parts - one at at time - with the original items if you still have them. New parts have been known to be faulty out of the box. You did say you had tried 3 replacements and the odds are they wouldn't all be bad. Still, it has to be something to cause an electrical failure.

 

[J_J]

Here is the diagram of a common ign circuit.

If you connect things correctly, and do the test we have stated, you should have diagnosed and fixed the problem.

To eliminate the switch, jump directly from the Batt, and have the points opened, and then put the screw driver touching the two points and remove them. A spark should occur if parts are good, and connected correctly.

A shorted capacitor will keep the current flowing and not allow spark. You can remove it for testing. It is only used to keep the points from arcing/sparking and pitting.

I believe the ign switch only provides voltage to the coil, and the start button only starts the tractor.


Diagram.

 

[catfishonly]

Thanks all for your help but i think i have found the problem. I tested the breaker plate withe the points open and it was grounded out at the brass screw and the cooper strip the insulation seems to have rotten.But after this fix i will keep you informed if this works.

 

[Soundguy]

points should be set a .020 . make shure the points will open and close if they don't close no fire. also do you have good coil and plug wires? has this tractor ran lately?

points on a front mount set to .015 NOT .02

points on a side mount set to .025


ALL plugs gap at .025 on the 4 cyl fords pre 65..

soundguy

 

[Soundguy]

Thanks all for your help but i think i have found the problem. I tested the breaker plate withe the points open and it was grounded out at the brass screw and the cooper strip the insulation seems to have rotten.But after this fix i will keep you informed if this works.

you can get a new breaker plate.. or use a vylon grommet like a license plate plug / screw setup..

 

[catfishonly]

put in new breaker plate and it did not help.I unhooked the resistor for a few minutes and got fire. i have three resistors that are the same. Can you tell me what value resistor i need. I know i need the resistor inline or it will smoke the coil but is everyone for sure they are not makeing the coil with one inside of it now. I bought the coil from TSC.