Ford 860 - Intermittent spark - HELP!

Good morning!

I have a new to me Ford 860. It is 12V with a 12V generator. (Haven't been able to test yet whether the generator is doing it's job.) The harness was so old that it was falling apart, so I replaced it and the coil, v-reg, condenser and ignition switch at the same time. (I know, one thing at a time is best....)

Now I can't get it to start, but at times it will cough and almost catch, or run for a couple of seconds with full choke, but then it dies.

If I hold the big wire from the top of the coil near the tractor and hold the button, a blue sparks jump a considerable gap, and they do it regularly, without any apparent misses.

But if I try the same with any of the 4 spark plug wires, I get a few sparks in a row, and then 1 or 2 rotations of the rotor seem not to send a spark. Doesn't seem to matter which of the 4 plug wires I try it with.

Here is what I know: The battery was brand new and fully charged. The smaller wire from the coil to the distributor seems not to be shorted anywhere at the dist body. Cap and rotor are new from NAPA and seem to be playing well together.

The tractor is a long drive from my house, and I don't have internet access or electricity where it is kept, so I'd like to have a clear cut idea of what I am going to check next or replace next to figure this thing out.

Any suggestions? Thanks a lot!

Jeff

First thought, it the little key installed between the rotor and the dist shaft to keep the rotor in time?

Is the cap dry and have no carbon trails, and the rotor contacts clean and able to make contact with the cap? Are your spark wires breaking down and going bad?

You seem to have a blue spark going into the distrib from the coil and not coming out???

OR... is the resistor breaking down or the key switch going high causing the 12 volts to drop going to the coil?

Check the rotor shaft for side play. If it is excessive, you will get a intermittent spark to the plugs. If so, you will need to replace bushings in distributor or replace it.

Thank you for taking the time to help!

The little clip that holds the rotor in place is there, and everything is new/clean. The plug wires themselves are good quality and new, and worked fine last fall before I started down the rabbit hole of replacing the harness and other parts.

There seems to be good spark going IN to the distributor, but not coming out.....

Jeff

I took the distributor off and cleaned it and checked for play in the shaft, and it seems good....

Thanks again,
Jeff

"I took the distributor off" Is the cap in the proper position. This day and age, caps and distributors don't always fit real good!

I am pretty everything is good with the cap position.

Also, I have the rotor hitting the #1 post at 5 degrees on the flywheel, and the points are just starting to open, so I think timing is good. But unfortunately, I'm at a point where timing doesn't really even matter, because the spark plugs aren't firing regularly.

Could bad points or a bad condenser cause this?

Thanks!
JEff

I would try a new set of points, (good quality) and a condenser. You have just about exhausted everything else.

Borrow a coil from someone. They can be intermittent if going bad. It can drive you batty trying to find the problem.

I have also said this many times when all else fails. Wait until it is good and dark, crank the tractor and look for stray high voltage leaks.

I missed part you your ip. Put your old coil back on. Also drain your carburetor bowl and make sure the flow to the bowl is adequate.

I guess I kind of jumped around. You said it will at least fire with the choke pulled out. You might not have an electrical problem.

Do check the point gap and run an ignition file over them if they are old points. Be sure to take a piece of paper towel/clean cloth to wipe the points. If there is no improvement then do the following:

Turn off the fuel valve and measure how much gas is in the bowl when you drain it. Then turn the valve open and see if there is enough flow to fill about a cup in about 2-3 minutes.

Have you cleaned the air filter and changed the oil in the filter cup?

If you are convinced you have good spark at the coil tower than coil wire, distributor cap, rotor or plug wires get you to the end, "spark plugs???"

I hope you can retrieve old parts. Use a jumper wire from battery to coil. Still no joy? Reinstall old coil. No? Reinstall old points and condenser. Old parts are preferred because modern point ignition parts are often bad right out of the box and getting a second bad one can really lead to some head scratching.

I think your best bet is the Pertronics electronic ignition swap. Mine works great.

I recently wasted a couple of weeks on a similar problem with my 4000. I had replaced points and condensor with a set from TSC, but it turns out the condensor was bad and caused the points to fail. The tractor started immediately after I installed new parts from CNH.

Thanks for the help, everyone.

I'll try a new, new set of points and condenser and see what happens........

Jeff

Someone here said a lot of new condensers are bad right out of the box.

Someone here said a lot of new condensers are bad right out of the box.

Recently had a similar issue with our 860 Found the brass tab or connector on the distributor that connects the coil wire to the points cracked, weakened. Apparently over the years of point replacement and use only hanging on about 1/4 the original width. Replaced it cured it. Just a something else to check.

Thanks! I'll check that, too. Jeff

(quoted from post at 06:14:48
05/14/18) Recently had a similar issue with our 860 Found the brass tab or connector on the distributor that connects the coil wire to the points cracked, weakened. Apparently over the years of point replacement and use only hanging on about 1/4 the original width. Replaced it cured it. Just a something else to check.

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