Continued ignition problems.

[cumbres]

I wrote recently with some issues with frequent failures of our ignition system, specifically the points and condensor. There was a recommendation to get a NAPA ic14-SB coil. This is a 52 8N with sidemount distributor and 12 volt conversion.

Well we did that and we had another failure within a couple of hours of operation. Tonight we measured ohms. The current Napa coil we have, a IC14 without the SB has 3.2 ohms resistance. We put another ohm of resistance in line to try to decrease our amps a little bit. With the engine not running the ignition pulled 2.5 amps through our digital multimeter. We could not get a reading with it running.

Investigating things tonight I came across this discussion from September:
http://www.ytmag.com/cgi-bin/viewit.cgi?bd=nboard&th=730703

It appears that we should have had enough resistance in the circut before adding the ohm of extra resistance.

The other comment made in that discussion is a question if the alternator had issues that it could overheat the points/condensor. Is there an easy way to test? Our alternator is a 3 wire. It was wired incorrectly when we got the tractor and I have wondered if it could potentially be part of the problem. It puts out about 14.5 volts when running and does a good job of keeping the battery charged.

Any help appreciated.

 

[JMOR]

(quoted from post at 00:12:22 07/02/10) I wrote recently with some issues with frequent failures of our ignition system, specifically the points and condensor. There was a recommendation to get a NAPA ic14-SB coil. This is a 52 8N with sidemount distributor and 12 volt conversion.

Well we did that and we had another failure within a couple of hours of operation. Tonight we measured ohms. The current Napa coil we have, a IC14 without the SB has 3.2 ohms resistance. We put another ohm of resistance in line to try to decrease our amps a little bit. With the engine not running the ignition pulled 2.5 amps through our digital multimeter. We could not get a reading with it running.

Investigating things tonight I came across this discussion from September:
http://www.ytmag.com/cgi-bin/viewit.cgi?bd=nboard&th=730703

It appears that we should have had enough resistance in the circut before adding the ohm of extra resistance.

The other comment made in that discussion is a question if the alternator had issues that it could overheat the points/condensor. Is there an easy way to test? Our alternator is a 3 wire. It was wired incorrectly when we got the tractor and I have wondered if it could potentially be part of the problem. It puts out about 14.5 volts when running and does a good job of keeping the battery charged.

Any help appreciated.

What was the nature of the failure???
"Well we did that and we had another failure within a couple of hours of operation."

 

[cumbres]

We have either the points quit working or the condensor fails. We have replaced each at least 3 times. Also replaced the distributor cap. Had another fellow double check all the wiring. Normally tractor start to bark loudly and start to require some chock to run normally. Replacing these parts completly fixes the bark and also gets the motor running after it dies. We have also replaced the ignition switch when it failed about 5 months ago.

Curious thing I forgot to mention was that the Ford folks recommended going back to a 6 volt coil with 2 dropping resistors. The 2 that were recommended were only 0.5 ohms each for a total of 1 ohm. The coil itself was either 1 or 1.1 ohms. We thought that that might create too many amps through the points/condensor since I believe I have read that it is important to limit the amps to less then 3.5.

 

[JMOR]

What was symptom that caused you to declare condenser bad?
Points: What does "points quit working" mean?
I'm looking for details.

 

[cumbres]

Points appear burned. Condensor did not check out with ohm meter.

 

[JMOR]

Points appear burned. Condensor did not check out with ohm meter.[/quote]
Points can look awful & still conduct current. Condenser only needs to look open with an ohmmeter & if analog type meter have a momentary needle deflection when leads are reversed, using a high ohms scale. May see nothing on Rx1 scale. Obviously, I am questioning whether or not you have homed in on your problem. I'm not convinced at this point.

 

[Dunk]

Yall got some skinny posts...

 

[36 Coupe]

Dufus tries to check condensers with a 1.5 volt battery.He dosent know there is 200 to 300 volts applied to a condenser when the points open.He dosent know that condensors develope leakage and new condensors fail fast because the insulation fails.I have been in electronics since 1951 and have always tested condensors by applying a working voltage and looking for leakage with a voltmeter.

 

[JMOR]

Well, maybe after he has been "in electronics" for 60 years, he won't be a "Dufus" anymore & will turn out to be a nice accommodating fella trying to help those with less experience. Personally, I bet 98% of condensers replaced are perfectly good and will bank on a 75% number. There is something else going on here. One of several possibilities is that it isn't ignition at all. Need to check to see if there is a spark at the next instant after it stops running.
As for explaining why it appears the new points/condenser appear to temporarily fix the problem....well, time is one factor, as it has a cooling period for numerous things to change. Another is that in replacing the points/condenser, something else is "touched"........that "touching" may make a 'temporary repair'.......an example or two would be the copper strip between the insulated feed thru terminal & the points or the insulated terminal's insulator.....
We/he/you really need to know whether the spark is actually non-existent at the instant of "no run" or not. It is insufficient to know that changing some things makes it run for a little while.

 

[oldtanker]

I don't know about the 75% #. I do know that I worked on alot of cars in the 70's that the points burned up. Ask the owner when the last time they changed the points and condenser.....you would get "well I just changed the points, the condenser looked good so I didn't do anything with it". Put in new points and condenser and the car would be back up and running.

As far as the points burning up in this fella's tractor I'd start looking for a ground problem. If as he says it has new points, condenser and coil, peoper voltage and ohms where it's supposed to then it has to be something else.

Rick

 

[cumbres]

I know you are not convinced. I am totally convinced these parts are the ones that are failing and preventing the engine from running. They have been checked as you stated. Also, when the tractor stops, it will not run again until the condensor and sometimes both condensor and points are replaced. Fuel and air are fine. Always have electricity to the coil and coming out of the coil. But the sparks at the plugs do get weak. BTW, plugs were replaced during this process also since the old ones were, well old!

What I don't know is why these keep failing. I have never had an engine that has been so resistant to becoming a reliable performer. I do believe there is some other problem that I haven't found. But what I have not figured out. That's why I asked.

 

[cumbres]

Ok, I see there are some more posts I didn't see before.

I have considered that something else is a problem or getting hot. The first time we had this problem I had to wait overnight because It would not restart. After a parts run I came back and tried to restart the engine when it was totally cold. No fire, and I don't believe hardly any sparks at the plug. When I put the new parts in and put the cap back on it fired up immeadiately and ran for several weeks.

The little copper tab did break off recently (inside distributor) and is currently replaced with a short wire that is not touching anything it shouldn't.

I have checked and rechecked the connections for plug wires and coil wire. They are good.

The inside of the replaced distributor cap showed some darkening on the posts. It was replaced as a desperation issue but hasn't had any significant change in symptoms.

The tractor is completely rewired since when we got it the alternator was connected only to the ignition system. Curiously it was only putting out about 3-4 volts. After rewiring it started to put out a normal 14.5 volts or so. The battery was isolated from the ignition and only was in circut with the starter. This explained the previous owners comment that he had to occasionally charge the battery since it seemed to get weak, especially in the winter.

The link in my original email was for another person who was having similar problems and there was mention that potentially the alternator was part of the problem. Does any one have thought about that being the true reason for our problems?

Thanks guys.

 

[Jerry/MT]

Was the shut down abrupt, as if you turned off the key, or did it sputter and cough and then quit? If it coughed and sputtered, it may be fuel related.
Perhaps you"ve all ready done this, but have you checked for spark IMMEDIATELY after the engine shut down? (Checking for spark means pulling the center wire from the distributor cap, holding it near a good ground, and trying to start.
Immediately means getting right off the seat and checking for spark after the engine quits, not walking back to the shop to get some tools.)
Feel along the primary circuit wiring and components for any "hot spots " that indicate high resistance.
Have you checked for any loose connections in the distributor or anywhere else that might open the primary circuit?
In my experience, digital voltmeters are unreliable for use on a running engine of this vintage(they may work on modern vehicles)due to RF interference, I believe. Try a cheap little analog meter.

What current did the ignition system pull, not running, with the points closed BEFORE you added resistance?

You need to figure out the root cause of this problem and quit throwing parts at it until you find the source of the problem. Changing points and condensors is masking the root cause.

 

[cumbres]

(quoted from post at 00:19:38 07/03/10) Was the shut down abrupt, as if you turned off the key, or did it sputter and cough and then quit? If it coughed and sputtered, it may be fuel related.
Perhaps you"ve all ready done this, but have you checked for spark IMMEDIATELY after the engine shut down? (Checking for spark means pulling the center wire from the distributor cap, holding it near a good ground, and trying to start.
Immediately means getting right off the seat and checking for spark after the engine quits, not walking back to the shop to get some tools.)
Feel along the primary circuit wiring and components for any "hot spots " that indicate high resistance.
Have you checked for any loose connections in the distributor or anywhere else that might open the primary circuit?
In my experience, digital voltmeters are unreliable for use on a running engine of this vintage(they may work on modern vehicles)due to RF interference, I believe. Try a cheap little analog meter.

What current did the ignition system pull, not running, with the points closed BEFORE you added resistance?

You need to figure out the root cause of this problem and quit throwing parts at it until you find the source of the problem. Changing points and condensors is masking the root cause.

The symptoms are normally the same. After the engine has about 5-15 hours or so on it you start to hear the exhaust develope a sharp bark sound to it that slowly becomes more noticable. After awhile it needs a little bit of choke to continue to run. The exhaust gets dark because it is overfueled but it will run better and the governor does not hunt. Then, it quits. This process can occur over several operating sessions. If it was barking when shut off for the day it will do the same when it is restarted the next day.

I checked the amps with the resistance and 12 volt coil. Was 2.5 amps on a multimeter. I do not have a amp pull on the multimeter for the previous system but the amp meter on the tractor appeared to be pulling more then 5 amps when the ignition switch was closed.

If the ignition is replaced this engine always starts on the first try unless the choke is mishandled. The governor will hunt for about 15-20 seconds and then it settles down and runs well. It does not appear to miss. The only other thing I just discovered is a exhaust header leak for cylinder #4.

I have been through the fuel system from tank to carb and in the carb. no restrictions, float is ok and appears to be adjusted correctly. Needle valve is free and in near new condition. air intake is open.

Always end up back to ignition. I agree with the need to not keep throwing parts at it. I realize the ignition failure is secondary to another cause, but I am at a loss what that cause is, unless our extra resistance in the ignition circut helps.

But we will probably have to keep throwing some parts at it since it is needed for grounds care so getting it operating quickly is a higher priority for the owner then it being down for an extended period of time for debugging. Also, I am not the main operator so doing immeadiate debugging is more difficult for me. About the longest I can keep it is for an evening or two.

Cumbres

 

[Jerry/MT]

There"s a lot more to the ignition than just the points and condensor. The whole electrical system is involved since it supplies the power for the ignition. That"s why I asked about the immediate check for loss of spark when this problem occurs. If that"s what is happening then it"s electrically related. Try feeling for hot components, look for a way to temporarily monitor voltage at the coil. If the voltage regulation goes wonky that can increase primary ignition current causing the coil to overheat and points to burn. The coil will feel hot and may show an open circuit or internal short until it cools down. If it"s intermittent, then it"s very hard to diagnose without some real time monitoring.

You said that you have a manifold leak at the #4 exhaust. Since the intake and exhaust manifold are close coupled, are you sure that you don"t also have an intake air leak? Your shut down description sounds more fuel related than ignition related. The fact that it runs with choke seems to support that but weak spark can be helped by fuel enrichment. Have you looked at the plugs to see what they might be telling you?


This is a very puzzling problem and it"s hard to diagnose from a distance. There are a lot of experienced people than can help on this forum but more data is needed. This old equipmet has infinetly more failure modes that if it was brand new or had relatively low hours on it and thus takes more time to trouble shoot. Keeping an open mind as to the cause will help you from jumping to conclusions as to what it might be.(It"s easier for me to do since I"m not directly affected by loosing the use of the tractor!)

Good Luck and keeping coming back. We"ll beat this thing yet!

 

[cumbres]

(quoted from post at 04:11:57 07/03/10)
This is a very puzzling problem and it"s hard to diagnose from a distance. There are a lot of experienced people than can help on this forum but more data is needed. This old equipmet has infinetly more failure modes that if it was brand new or had relatively low hours on it and thus takes more time to trouble shoot. Keeping an open mind as to the cause will help you from jumping to conclusions as to what it might be.(It"s easier for me to do since I"m not directly affected by loosing the use of the tractor!)

Good Luck and keeping coming back. We"ll beat this thing yet!

I appreciate the kind words. What really confuses me, is until the barking starts, the tractor runs great. It starts on the first try, it really purrs. Has good power and doesn't really seem to use much oil. Exhaust doesn't smoke. It leaked a little bit at the oil drain but a gasked fixed that. I'll try to take a closer look at the intake this coming week. But it is supposed to rain most of the time so may not know much this week.

So, I was reviewing all the parts of the tractor that I have been into. About the only thing I haven't worked on is the steering, engine block/valves, governor, transmission. Everything else is serviced and flushed. The wiring is all new since the old was all screwed up. In the ignition system the only parts that haven't been touched is the distributor shaft that runs into the engine. The previous owner had put on a new carburetor shortly before our church bought it. I did go through it to check adjustments, float levels, etc. The first time it failed, I rechecked these and they were fine. The plugs are normal color when pulled, not black, not white, just a nice normal dark color.

Now, I have a pet theory. Tell me if it is screwy. The Alternator that is on the tractor was hooked up ONLY to the ignition when we bought it. Figured that out when I couldn't figure out why the alternator didn't charge the battery. When I delved into it the alternator was only reading 3-4 volts output. We rewired it so it charges and does all that it should. It appears to put out 14.5 volts now. But, in the link in my very first message there was a comment about an alternator frying ignition parts if some of the diodes in the alternator were screwed up. I have not taken the alternator to a shop to look at that possibility since it appeared to be working ok.

Does this seem possible?

When watching the amp meter when I start the tractor I get a surge to 10-15 amp charge that quickly backs down to 0 after the engine has run a short time. So from that I figure the regulator is working ok. The battery also does not appear to be overcharging.

Thanks!

Cumbres

 

[JMOR]

I would expect that when you were measuring 3-4volts on alternator output (connected to coil), that all you were doing was measuring coil primary voltage, not alternator output, as at that time the alternator was outputting nothing.Now, to fully answer that, I need to know what wiring changes did you did to the alternator?