Ford Jubilee No Spark Condition

[NS-JG-Jubilee]

I've spent a bit of time looking around these forums and found the advice here quite helpful, so I'd figured I'd post to see if anyone might have a solution to this issue.

I've got a Ford Jubilee with a no-spark condition.

Several weeks ago, the tractor was idling while we prepared an implement and it suddenly quit. No backfiring or sputtering, it just quit as though the key had been shut off. Typically when this has happened, the tractor was just out of gas and needed to be refilled. Not so this time.

After filling the gas tank, we drained the battery trying to start it. The engine was cranking (I hope I'm using the right term here) but wasn't starting or even trying to.

At this point, I began diagnosing the ignition system. I checked all the spark plug wires for continuity, and they all passed. I also put a circuit tester between the ignition coil and points to check that the points were working, and the light flashed when the engine was cranked, so I ruled that out. I also tested the ignition coil, and it yielded a bright blue spark. I also replaced all four spark plugs. I checked the continuity on the rotor button, which was good. And I checked the continuity on the posts on the distributor cap, which was also good.

Eventually, I determined that the coil was sending a good spark to the distributor cap, but the spark wasn't being distributed to the spark plug wires.

After consulting with a mechanic friend, I also replaced the condenser and points, gapping them as per specification. I also replaced the battery. I set the timing by turning the flywheel to 8°BTDC as per the indexing marks, and then gently turned the loosened distributor while cranking to try and get the engine to catch. I did this because I thought that somehow the rotor may have gotten out of phase with the posts for the spark plug wires. Still no luck. I've also manually checked to see that spark is getting into the distributor cap by grounding the terminal, and I also manually crossed the centre post in the distributor cap to a spark plug wire post to check and see that spark could in fact go to the spark plug wires and it did.

At this point, everything points to either a faulty rotor button (which seems unlikely given that it has continuity and is in good shape), or that the rotor is out of phase with the posts on the distributor cap. I can order a new cap and button, but seeing as neither seems to actually be broken, I'm a bit reluctant to do so. This afternoon, I'm going to try and adjust the timing once more just to make sure I got it right, but I was wondering if any of you might have some other ideas as to something I'm missing?

I'd appreciate any insights.

-JG

 

[Jim.ME]

Is the center contact in the cap for the rotor button there? I have seen those fall out or break up. Is the arm on the rotor up high enough to contact the center contact of the cap? Is the shaft clip in place that the rotor slides on over?

 

[NS-JG-Jubilee]

Thank you for your comment. From what I can
see, the centre contact is still intact.
Also, for the record, I have a second
Jubilee for parts, and I have tried both
rotors and both caps from both tractors. I
have tried prying up the arm on the rotor
some to make sure it will make contact, and
the clip for the rotor is in place. That
being said, I wonder if it wouldn't hurt to
pry it up more than I have before to be
100% certain it is making contact.

 

[Jim L WA]

NS, You said,"Eventually, I determined that the coil was sending a good spark to the distributor cap, but the spark wasn't being distributed to the spark plug wires." How did you determine that? Oh, I just had a thought. Have you cranked the engine over with the distributor cap off to see if the rotor is actually turning. BTW timing has nothing to do with a no spark condition.

 

[NS-JG-Jubilee]

Thanks for you reply. To see if there was spark coming from the ignition coil, I just pulled the centre wire from the distributor and grounded it against the frame - there was a strong blue spark. I also grounded the centre point of the distributor cap when I had it off, and it sparked, so I know it's getting inside the cap and hopefully onto the rotor button. I've also cranked the engine with the cap off, and the rotor is turning.

Perhaps I was using the wrong terminology when I said timing. My thinking was that because the distributor housing can be rotated independently of the rotor and shaft, the posts inside the distributor cap may have been out of phase with the rotor, that is, the rotor was only sparking when it was between the posts going to the spark plugs. That is the only explanation I've been able to come up with for why there's no spark to the sparkplugs. That's why I set the flywheel to 8° BTDC and then lined the distributor up so that the rotor was pointing to the number one sparkplug wire post in that position.

 

[JMOR]

(quoted from post at 15:28:14 02/07/21) Thanks for you reply. To see if there was spark coming from the ignition coil, I just pulled the centre wire from the distributor and grounded it against the frame - there was a strong blue spark. I also grounded the centre point of the distributor cap when I had it off, and it sparked, so I know it's getting inside the cap and hopefully onto the rotor button. I've also cranked the engine with the cap off, and the rotor is turning.

Perhaps I was using the wrong terminology when I said timing. My thinking was that because the distributor housing can be rotated independently of the rotor and shaft, the posts inside the distributor cap may have been out of phase with the rotor, that is, the rotor was only sparking when it was between the posts going to the spark plugs. That is the only explanation I've been able to come up with for why there's no spark to the sparkplugs. That's why I set the flywheel to 8 BTDC and then lined the distributor up so that the rotor was pointing to the number one sparkplug wire post in that position.

ave you moved the position of plug wires in cap since it last ran? #1 will be at TDC BOTH on exhaust and compression strokes. For timing, you MUST be on compression stroke. If on exhaust stroke, rotor will be 1/2 turn away from #1, assuming that you have not moved wires in cap.

 

[phil(va)]

Do you have the dust cover installed? If no dust cover, the rotor may indeed not be in the correct position to make contact.

 

[JMOR]

No "contact", just close. Plus, a dust cover would only move further away from "contact'. Hard to comprehend some posters! :roll:

 

[Jim L WA]

I see that you have determined that spark is getting into the cap, but I don't see what you have done to know that you aren't getting spark to the plugs.

 

[NS-JG-Jubilee]

Yes, the dust cover is installed and seated properly.

 

[NS-JG-Jubilee]

In order to find that out, I pulled a spark plug wire and held it near a grounding point on the frame. There was no spark jumping, from the sparkplug wire.

 

[NS-JG-Jubilee]

Just an update:

Today, I finally managed to get some spark to the plugs, but still can't get it to start, but I think this is just because I need some fine tuning - I didn't have time to work on it any further today.

I turned the flywheel to 8°BTDC, lined the rotor up with the number one plug wire on the distributor cap, and then clipped a test light on to the negative side of the ignition coil where it connects to the contacts. This way I was able to turn the distributor ever so slightly to see when the contacts were closing. Then, once I had narrowed it to there, I held the number one spark plug wire near a grounding point and rotated the distributor until I saw a spark. So now I know that there is spark going to the plugs. It seems that even if the rotor was pointing to the right plug wire, it was out of sync with the points opening and inducing the high voltage spark in the ignition coil.

Hopefully I should be able to get the tractor to start tomorrow by cranking it while adjusting the distributor very slightly, and from there I can set the timing by ear until I get a test light.

I'll be sure to post if and when I can get it started.

 

[JMOR]

(quoted from post at 18:54:11 02/08/21) Just an update:

Today, I finally managed to get some spark to the plugs, but still can't get it to start, but I think this is just because I need some fine tuning - I didn't have time to work on it any further today.

I turned the flywheel to 8BTDC, lined the rotor up with the number one plug wire on the distributor cap, and then clipped a test light on to the negative side of the ignition coil where it connects to the contacts. This way I was able to turn the distributor ever so slightly to see when the contacts were closing. Then, once I had narrowed it to there, I held the number one spark plug wire near a grounding point and rotated the distributor until I saw a spark. So now I know that there is spark going to the plugs. It seems that even if the rotor was pointing to the right plug wire, it was out of sync with the points opening and inducing the high voltage spark in the ignition coil.

Hopefully I should be able to get the tractor to start tomorrow by cranking it while adjusting the distributor very slightly, and from there I can set the timing by ear until I get a test light.

I'll be sure to post if and when I can get it started.

asked earlier, but will try again , as this and answers may save you time & aggravation. "Have you moved the position of plug wires in cap since it last ran? #1 will be at TDC BOTH on exhaust and compression strokes. For timing, you MUST be on compression stroke. If on exhaust stroke, rotor will be 1/2 turn away from #1, assuming that you have not moved wires in cap."

 

[Sean in PA]

It doesn't spark when the points close. It sparks when they open.

 

[Jim L WA]

Good point Sean.