Ford 8N having trouble starting -- many troubleshooting steps take -- suggestions?

   / Ford 8N having trouble starting -- many troubleshooting steps take -- suggestions?
  • Thread Starter
#501  
Thanks for the confirmation. I was able to test the points off of the tractor and find out that they indeed were not sparking. Tightening them up a bit and using a .015 shim to make sure they are gapped correctly was the trick -- they sparked just fine and I popped the distributor back on the tractor. She started right up but still had the stumble/miss. Bugger. So I recorded taking off each spark plug wire that was previously suggested here. If you watch the video you will see that when pulling the wire from all 4 cylinders it stumbled worse and in a different way.

Any other troubleshooting you can think of? Thanks for all of your patience so far.

 
   / Ford 8N having trouble starting -- many troubleshooting steps take -- suggestions? #502  
The first thing is to manipulate the engine wiring harness ,with engine running to see if there is a bad /loose connection giving you an engine miss from vibration.If that seems good , redo the pulling plug wires & pay very close attention to how much each cylinder changes the engine RPM ,to locate which cylinder's are miss firing (usually there is only one ) might only show up as slight difference, this is easier if you had a tachometer& could watch RPM
 
   / Ford 8N having trouble starting -- many troubleshooting steps take -- suggestions? #503  
502 reply's and it still don't run. Have you checked for air leak yet?
 
   / Ford 8N having trouble starting -- many troubleshooting steps take -- suggestions? #504  
PorkChops:

Do you have a vacuum gauge? I do not remember if the 8n has a port on the intake manifold to pull vac, but if it does, it would be worth seeing what your vac is reading at idle and if the needle is steady or bouncing.
 
   / Ford 8N having trouble starting -- many troubleshooting steps take -- suggestions? #505  
PorkChops:

Do you have a vacuum gauge? I do not recall if the 8n has a vac. port on the intake manifold, but if it does, it would be worth getting a reading at idle. Also looking to see if the needle is bouncing at all. That will tell you if the timing is off, or if you have a vac. leak anywhere.

Man you did have some rain.
 
   / Ford 8N having trouble starting -- many troubleshooting steps take -- suggestions?
  • Thread Starter
#506  
I don't have a vacuum gauge but I think you guys are on the right track -- I know it's been mentioned before but I think I might have a manifold crack. A neighbor came over who is familiar with tractors, not necessarily the 8N, but is mechanical in nature. I showed him how the tractor will still run when pulling the main needle out or screwing it in all the way. He said "it's got to be getting air in some way" and put his hands behind the manifold. Said he could feel some warm puffs of air. I didn't have the time at the moment but tonight or tomorrow night I will fire her up and do as someone suggested a few pages ago -- spray some starting fluid around the manifold and see if the firing changes, surges, etc. I should have done this a while ago, my apologies.

Will let you all know how it goes. I am off to research how hard it is to replace a manifold!
 
   / Ford 8N having trouble starting -- many troubleshooting steps take -- suggestions? #507  
an exhaust side leakl doesn't specifically mena a vac leak.. however..

IF you can put the fuel screw all the way in and she runs.. i still say carb has an issue..
 
   / Ford 8N having trouble starting -- many troubleshooting steps take -- suggestions? #508  
It's not hard at all. What I did when I replaced my manifold gaskets back in January was spray down the 4 manifold nuts with pb blaster a day or so beforehand. Mine came out rather easily. 2 nuts holding the carb and a couple of linkage rods. The manifold itself is only 4 nuts, the studs are threaded into the block I believe some are into the water jacket. You'll have to obviously drop the exhaust as well. I took a cup brush on my drill and cleaned up the mani and the block mating surfaces. I don't think the whole job took me much more than an hour and I was in the middle of a six pack when I started. After everything was buttoned up she sounded like new, previously she sounded almost like a miss ans quite loud. FYI after a good pb soaking I took time and loosened and tightened the nuts back and forth so I wouldn't snap a stud off. Seemed to work for me.

I know it's frustrating as all get out. Stick with it! If your mani gaskets are shot you should be able to hear it as well as see some soot on the block. Keep with it and you'll get it. I think it's a safe assumption that we all want to get this thing running well again. Good luck and keep us posted.
P.S. keep listening to Soundguy's advice he knows his stuff
 
   / Ford 8N having trouble starting -- many troubleshooting steps take -- suggestions?
  • Thread Starter
#509  
8N Ren -- good to know. I hope to be that deep into a six pack if I have to work on this anymore.

The next time I get a chance to look at it I will take pictures of the manifold, too. It is heavily pitted on the outside, who knows what it looks like next to the block.

Soundguy -- I have the rebuild kit for my carb. Once I test the manifold with starter fluid I guess I will know which way to go next -- start looking at the manifold or carb. What's crazy is it ran the same way with someone's different carb.

The tractor did get to help out this weekend, it was just running with the stumble/miss while doing it.

Before:
img20130420111352.jpg


After (still not done):
img20130420191111.jpg
 
   / Ford 8N having trouble starting -- many troubleshooting steps take -- suggestions? #510  
I don't have a vacuum gauge but I think you guys are on the right track -- I know it's been mentioned before but I think I might have a manifold crack. A neighbor came over who is familiar with tractors, not necessarily the 8N, but is mechanical in nature. I showed him how the tractor will still run when pulling the main needle out or screwing it in all the way. He said "it's got to be getting air in some way" and put his hands behind the manifold. Said he could feel some warm puffs of air. I didn't have the time at the moment but tonight or tomorrow night I will fire her up and do as someone suggested a few pages ago -- spray some starting fluid around the manifold and see if the firing changes, surges, etc. I should have done this a while ago, my apologies.

Will let you all know how it goes. I am off to research how hard it is to replace a manifold!

Don't use starting fluid, carb cleaner, or anything like that. They have a low flash point.
 
 
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