Help - My Ford 8n won't start

ModelAguy

New User
Hello everyone. This is my first post and I would like to thank all of you ahead of time for assisting me in this problem that has left me stumped. I have been working on anything mechanical since I was a kid and yet this one has left me scratching my head.

Here is the scenario;
I have 1949 Ford 8n. It had been sitting in a shed for several years when I purchased it a couple years ago. When I got it, it was 6 volt and no obvious signs of problems. First I went through all the normal stuff to bring something back to life and got it running and driving. Then I decided to covert it to 12 volt. I used a complete kit that I purchased on ebay that had a high purchase history. I installed the 12 volt system along with a 12 volt battery and it started up wonderful. I ran it a little with no problems over the course of a couple months. It had a bad rear tire so I parked it at the end of this last summer (warmer weather) and put it under a tarp until I could get another tire (had to do some rim welding etc). Then in the fall (cooler weather) I got the tire mounted and wanted to put one of the implements on it so I went to start it but to no avail. I started the regular routine and checked for air fuel and spark. Air was fine. It had spark at all spark plugs. The fuel seemed a little restricted from the settling bowl valve so I replaced the whole settling bowl. Still no start. I tried some shots of either, still no start. A few times it acted like it was trying but still no start. I came back to it a few times over the following months but had the same result. There was one time that it finally started but it was VERY difficult and not like it should nor like it had been before I parked it for the couple month for the tire issue. During this time I took of, disassembled, and cleaned the carb a couple times as well. I also checked compression at a dead cold (about 32 F) and lowest was 95+ and the other three were 110+.
What could be the problem, or what could have changed from the time that I put it under the tarp to do the tire work? I have been told quality of spark could be an issue but how can I test for this? Besides most everything in the electrical system is new for the 12 volt system here is a link to the kit that I bought on ebay-

http://www.ebay.com/itm/130945867076?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Again, it started and ran great for a while after I installed this kit.

If you have any suggestions let me know, I really appreciate it!
 

welcome, model A :)

where are u located? i am always reluctant to tarp things, it traps humidity.

why did u think the flow was restricted at the sediment bowl? it doesn't sound like fuel is your problem, or i'd have expected it to fire with ether. to test fuel delivery, removing the plug in the bottom of the carb and opening the valve of the sediment bowl should produce a stream that will fill a pint jar in 2 minutes.

i lean toward spark, others here will talk u thru that side of the diagnostics. have u had a look inside the distributor?
 
(quoted from post at 14:52:53 02/08/17) Hello everyone. This is my first post and I would like to thank all of you ahead of time for assisting me in this problem that has left me stumped. I have been working on anything mechanical since I was a kid and yet this one has left me scratching my head.

Here is the scenario;
I have 1949 Ford 8n. It had been sitting in a shed for several years when I purchased it a couple years ago. When I got it, it was 6 volt and no obvious signs of problems. First I went through all the normal stuff to bring something back to life and got it running and driving. Then I decided to covert it to 12 volt. I used a complete kit that I purchased on ebay that had a high purchase history. I installed the 12 volt system along with a 12 volt battery and it started up wonderful. I ran it a little with no problems over the course of a couple months. It had a bad rear tire so I parked it at the end of this last summer (warmer weather) and put it under a tarp until I could get another tire (had to do some rim welding etc). Then in the fall (cooler weather) I got the tire mounted and wanted to put one of the implements on it so I went to start it but to no avail. I started the regular routine and checked for air fuel and spark. Air was fine. It had spark at all spark plugs. The fuel seemed a little restricted from the settling bowl valve so I replaced the whole settling bowl. Still no start. I tried some shots of either, still no start. A few times it acted like it was trying but still no start. I came back to it a few times over the following months but had the same result. There was one time that it finally started but it was VERY difficult and not like it should nor like it had been before I parked it for the couple month for the tire issue. During this time I took of, disassembled, and cleaned the carb a couple times as well. I also checked compression at a dead cold (about 32 F) and lowest was 95+ and the other three were 110+.
What could be the problem, or what could have changed from the time that I put it under the tarp to do the tire work? I have been told quality of spark could be an issue but how can I test for this? Besides most everything in the electrical system is new for the 12 volt system here is a link to the kit that I bought on ebay-

http://www.ebay.com/itm/130945867076?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Again, it started and ran great for a while after I installed this kit.

If you have any suggestions let me know, I really appreciate it!

When is the last time you replaced the points, plugs, condenser, cap & rotor and set the timing?

It takes three things for an engine to run: spark at the right time, compression, & fuel/air in the right mixture. For the moment, forget about compression & concentrate on narrowing the problem down to spark or fuel.

There are three very important tools you always need to have in your N tool box: a 3 inch piece of wire w/ alligator clips on each end, a spark checker w/ an adjustable gap (* see below) and a 7/16 box end wrench. (see tip # 50 at the link below) And, you really do need a working ammeter on the tractor; it is a very important diagnostic tool. With these tools, you can quickly narrow down most N problems to spark or fuel.

Next time it won't start, check for spark then fuel. First, turn the key on, crank the engine & look at the ammeter. What is the needle doing? Does it show a constant discharge, no movement at all, or does it move back & forth slightly? Next, hook up your spark checker, turn the key on & crank the engine. If the spark jumps the 1/4” gap, you probably don’t have a spark problem. If it won’t jump the ¼” gap, you have a spark problem. If the ammeter needle shows a constant discharge, or doesn’t move at all, that also tells you that you have a spark problem. Jump the ignition switch w/ your jumper wire & see what happens. If it runs, you found the problem. If it doesn’t have spark after you jump the ignition switch, post back for more info on further troubleshooting. (and do not forget to turn the ignition switch off; see tip # 38

Next, check for fuel. Get a can & put it under the carb. Remove the bolt in the bottom of the carb; as long as the fuel is turned on, you should see gas flowing out of the carb. It should fill a pint jar in less than 2 minutes. If it’s a dribble, or runs for 5 seconds & stops, or none at all, you have solved half the problem: it’s fuel related. If gas flows well out of the carb & only stops when you turn it off at the sediment bowl, chances are very good it’s not a fuel problem .If it does not have gas coming out of the carb at a steady stream w/ the bolt out for at least 30 seconds, you have a fuel problem. First, remove the gas cap. Your vent could be clogged & it vacuum locked. If that doesn’t work, tap the carb bowl w/ a hammer handle in case the float is sticking closed. (don’t whack it w/ the head of the hammer; you can crack the bowl). If you still don’t see gas flowing, the N has three fuel screens; one in the brass elbow, one in the top of the sediment bowl & one on the stem of the sediment bowl in the gas tank. (see tip # 45) Check the screen in the elbow (see tip # 56) & the screen in the top of the sediment bowl. (don’t worry about the one in the tank) Both probably need to be cleaned. If you have the fuel knob turned on all the way, & 1 gallon or less in the tank, it may be trying to feed off of the reserve inlet which is probably clogged. Only open it 2 full turns. Put at least 2 gallons in the tank. (and do not forget to turn the gas off; see tip # 9)

There are ways to check for spark & fuel that work & ways that don't. For example, having gas to the carb is nice, but having it past the float is what counts! That’s why removing the 7/16” bolt in the bottom of the carb is the way to check for fuel. And, same thing w/ spark at the plugs. Some folks think that checking for spark means pulling a plug wire off & looking for one. Well, it's the distance the spark jumps at the plug that gives you the info you want. It takes about 17kv to jump a 3/16" gap & 22kv to jump ¼” in the open air. Remember, it’s 14psi outside of the engine & about 90psi at a 6:1 compression ratio in the cylinders & compressed air creates electrical resistance, so you really need the 17-22kv to fire the plugs when the engine is running. A store bought plug checker (in the picture) will work better than an old plug because it won’t shock the snot out of you like an old plug might!

Post back with results or more questions.

I've got a 1929 Tudor. You?



*If you don’t own a spark checker w/ an adjustable gap, buy one. In the meantime, an old spark plug w/ the gap opened to at least ¼” will work. Ground it to a rust & paint free spot on the engine turn the key on & look for a spark.
 

welcome, model A :)

where are u located? i am always reluctant to tarp things, it traps humidity.

why did u think the flow was restricted at the sediment bowl? it doesn't sound like fuel is your problem, or i'd have expected it to fire with ether. to test fuel delivery, removing the plug in the bottom of the carb and opening the valve of the sediment bowl should produce a stream that will fill a pint jar in 2 minutes.

i lean toward spark, others here will talk u thru that side of the diagnostics. have u had a look inside the distributor?[/quote]

Hello and thank you for your response.
I am just east of Kansas City Missouri. I agree that tarping is not the best idea but in this case I needed it in a place that I could work on the rear tire etc. and that was my only option.

The flow was definitely restricted because of the sediment bowl. I don't think that this was the culprit to my problem but it probably would have developed into one in the future. I replaced the Bowl so it would take that out of the equation anyway. I am definitely getting good gad flow.

I have not opened the distributer since the 12 volt conversion. (last summer) At that time I replaced points and wires and plugs etc.
Thanks again for your help
 

Hello, I have a 1930 Model A Deluxe Coupe that is my driver. I also have a late 31 coupe that is my long term project.

Just for clarity, it still is not starting. I have been working on my A instead for a couple months since I have been making more progress in that field lately! Ha!

Also I think the fuel seems just fine. It is filling the carb bowl easily. Any questions I had should have been taken care of after settling bowl replacement. Though I cant verify if it is drafting fuel up into the intake properly?

I replaced cap, rotor (front mount), points, coil, wires, plugs etc. when I did the 12 volt conversion. Everything worked well at that time. I never checked the timing, it seemed to start and run ok so I didn't go there. The ammeter has been working well. Before I had this problem I tested the overall charge to make sure that it wasn't overcharging due to a faulty or incorrect installation of one of the resistors that it has. Everything seemed fine at that time.

It does have spark. That is why I am scratching my head. I just don't know about the quality of spark. So far I have just checked the spark by grounding one of the plugs that has been in the head. I will try your trick of opening one up to 1/4" and see what happens.

Could you repost the link that you spoke about? I cant see it on the current post.

Also it will be this weekend before I try any of these fixes. It has turned cold here again but it is supposed to be better this weekend. I am trying to see if I can get some good direction before I go turning wrenches again!

Thanks again for all of your help!
 

Hello, I have a 1930 Model A Deluxe Coupe that is my driver. I also have a late 31 coupe that is my long term project.

Just for clarity, it still is not starting. I have been working on my A instead for a couple months since I have been making more progress in that field lately! Ha!

Also I think the fuel seems just fine. It is filling the carb bowl easily. Any questions I had should have been taken care of after settling bowl replacement. Though I cant verify if it is drafting fuel up into the intake properly?

I replaced cap, rotor (front mount), points, coil, wires, plugs etc. when I did the 12 volt conversion. Everything worked well at that time. I never checked the timing, it seemed to start and run ok so I didn't go there. The ammeter has been working well. Before I had this problem I tested the overall charge to make sure that it wasn't overcharging due to a faulty or incorrect installation of one of the resistors that it has. Everything seemed fine at that time.

It does have spark. That is why I am scratching my head. I just don't know about the quality of spark. So far I have just checked the spark by grounding one of the plugs that has been in the head. I will try your trick of opening one up to 1/4" and see what happens.

Could you repost the link that you spoke about? I cant see it on the current post.

Also it will be this weekend before I try any of these fixes. It has turned cold here again but it is supposed to be better this weekend. I am trying to see if I can get some good direction before I go turning wrenches again!

Thanks again for all of your help![/quote]

" It is filling the carb bowl easily."

That doesn't tell you much. Remove the bolt in the bottom of the carb & check for fuel flow.

" of one of the resistors that it has. "

It only needs the OEM ballast resistor and no others if you have a 12v coil. If you have a 12 volt coil, the OEM ballast resistor AND a fixed resistor that usually comes with these 12 volt conversion kits, you will have too much resistance in the ignition circuit and a weak spark.

" It does have spark"

Unless the spark jumps 1/4" in open air, you have a weak spark. While you're waiting for the weekend, put your battery on a charger; that will help with the spark.

" Though I cant verify if it is drafting fuel up into the intake properly?"

Get a can of starting fluid, remove the breather hose & spray it directly into the carb throat.

For some reason, this thread is not showing up in classic view & I can't get the link to most in modern view. So, go to any of my other posts and you will see the link: 75 Tips.
 
Which resistor is in the ignition circuit? If you have a 12 volt coil, all you need is the OEM ballast resistor.

And here is the link:
ballast_Bruce_zpsboeikaki.jpg

75 Tips
 
When you removed one of the spark plugs from the head, was it wet with fuel? If it was wet, I would pull them all and let them dry out, then clean them. Oil in the cylinder helps seal the rings and excessive fueling can wash that off causing problems.
 
If you have spark, air and fuel it should at least pop. And you said it was running well before it sat so my guess is that things were wired
up correctly. I'm assuming it is spinning strong when you try to start? The fact that you "cleaned the carb" makes me suspicious. Check
bowl. Fuel? Make sure your ignition switch is on. Done that before... Can get flooded quick too and then a bear. Very light shot of
starter fluid in each cylinder. Then if it pops you know it isn't getting gas. Just some basic thoughts. Best of luck.
 
" Very light shot of starter fluid in each cylinder. "

By the time you get the plugs back in & the wires on, it will have evaporated.

It's a lot more effective to spray it in the carb throat with the engine turning over.
75 Tips
 

[u:b2131f1757][b:b2131f1757]Good Report - Problem Solved!![/b:b2131f1757][/u:b2131f1757]

I would like to thank all of you for speaking up and giving your suggestions. Sometimes it helps me to speak to others and get some feedback in order to rattle my brain a little and get away from my "tunnel vision".

This is what took place and what I found out was wrong;
I double checked all of your suggestions -
1. pulled the plug an carb again and verified proper fuel flow. All good.
2. Pulled a plug and used an old plug spread 1/4 inch and verified that I did have spark. Spark was good and never missed a revolution while cranking.
3. I realized after all of your posting that I had wired it with both old and new resistors in line. I jumped past the new one and only kept the old one in place and cranked it over. Bam, the tractor started right up on only three cylinders and ran. (I still had the old plug that was gapped wide on one wire to see if removing the resistor would change the way the spark looked). I immediately replaced the good plug and now I'm up and running.
Funny thing is, why did it start ok before I parked it for those few months? I don't know, I guess it just wanted to run bad enough that it would start and run on a lesser spark. Anyway I'm glad it is all good to go now.

Thanks again for all of your help. I appreciate the links and photos as well. That all helped clear my thinking from being frustrated and helped me get back on track!
:D
 
" Funny thing is, why did it start ok before I parked it for those few months?"

Because the battery was strong enough to overcome the additional resistance in the circuit from the extra resistor.

Glad you got it running. Thanks for the follow-up.
75 Tips
 

glad to hear it :)

[b:5de1249462]"Funny thing is, why did it start ok before I parked it for those few months?"[/b:5de1249462]

my thinking is that the resistance of these ballast resistors (or something else in the ignition circuit?) can slowly increase over time, and somewhere in those months, the total resistance in the circuit finally crossed the line.
 

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