no spark at coil

Z-man

Member
I have a T030 and have no spark at the coil and the amp meter only moves a little when I turn the engine over it looks like the tractor has an old charging system and I just put on a new 12 volt regulator, the tractor has been sitting for some time before I got it and I"m not sure what is wrong
 
Said it once and will say it again. Coils do not work unless the point do and one that has sat for say 6 month or more the point most likely sat closed up so they have corroded and need cleaned or replace. Simple trouble shooting 101 and ya jumping on you a bit but the archives are full of the simple fix you most likely have. Still remember a guy who hired me to fix his TO-20 that did not run. Took me all of 15 minutes to clean the points and low and behold it started right up
 
If you need help finding out why she dont fire FIRST check the points for burned (filing may help) or mis gapped and then work through my troubleshooting procedure for the cause. AS LONG AS THE BATTERY HAS POWER, THE IGNITION SYSTEM STILL WORKS EVEN IF GENNY ISNT WORKING......

If you get the ignition working, then check out my Non Charging Troubleshooting

http://www.ytmag.com/cgi-bin/viewit.cgi?bd=jd&th=458743

John T
John Ts Ignition Troubleshooting
 
If you have a distributor clean the points as been mentioned. If it still doesn't start use a volt meter set on DC volts. With the points open and your ignition switch in the run position you should have battery voltage on both small terminals on your coil. If there no voltage present you need to check back at the switch for voltage. You could have a bad connection or broken wire. Hal
 
thanks, I have replaced all wires with new and I have spark on both positive and negative post of the coil with the wire on however the points are not moving at all and no spark on the coil wire to distributer cap?, when I ground the two small terminals on the coil it does have spark, I turn the switch off and no spark is present, so I believe the switch is good what next?
 
I wondered bout that with the points, if they don't move, the points in the dist don't move when I turn the engine, but have no spark at coil does this mean the new points or just clean they seem to move by hand (manual) but not when the starter is doing the turnin
 
If your spinning the engine over with the starter and the points do not open and close is the distributor shaft turning or not?? Had that happen to a IH 340. Found that the distributor gear had stripped out so would turn one time then not the next
 
just got back in from the shop and clean ground term plus points, however is it normal to have spark jump around or across the coil? and is it to be warmish to very warm to the touch
 
Common the have spark jump on the top of the coil. Well yes and no. If the top of the coil is dirty or wet yes if clean like it should be and dry no. But that could be part of your problem. I would clean it of with brake cleaner spray or carb cleaner spray or some such cleaner
 
both ends seem to jump toward center of coil like so I taped the center wore in hopes of stopping the spark but that didn't really help, what bout it getting warm?
 
QUESTION

"so I believe the switch is good what next?"

ANSWER

The points MUST be opening and closing which is caused by rotation of the distributor shaft and its cam lobes, is it turning and are points opening and closing????????????

Use a test lamp and put it on the coils small output to distributor terminal and turn IGN on and crank engine over, the light must flash ON (points open) and OFF (points closed).

Next if you work through my Troubleshooting Procedure theres a detailed step by step method to determine the cause of no spark, hope this and it helps.

Best wishes n God Bless

John T
Click Here
 
(quoted from post at 00:25:16 09/03/13) both ends seem to jump toward center of coil like so I taped the center wore in hopes of stopping the spark but that didn't really help, what bout it getting warm?
ut a wire in the center tower, connected to a gapped & grounded plug. Now it doesn't arc over at coil tower does it?
 
You need to look at the rubbing block on your points. Lack of lube on the lobes will wear the block. The points need to open and close. Hal
 
You probably need new points as the rubbing block is worn and causing your points not to open and close. Set them at .020" on the high point of your cam lobe in your distributor. Use some good lube on the lobes so your rubbing block doesn't wear so fast. Hal
 
A coil like most electrical stuff does in fact get warm. You may in fact have coil that has a crack on the top and if you o you will never stop that spark loss there
 
yea, it does arc over the coil, what does that mean and it gets warm to very warm when I have power to the battery cables
 
I have spark now, but I think the points need set to gap for best spark, however the coil is warm to very warm and spark jumps across the posts on the coil what does this mean, by the way would u happen to have the torque spec setting for a T030 z129 engine, connecting rods, head, mains, etc
 
so what your saying is the spark jumping across the posts is normal, would you happen to have the torque spec settings for a T030 z129 engine connecting rods, head, mains etc
 
do you know how to set the valves on a z129 engine? they look as if they could be set for best performance with a few simple tools?
 
Z, I have posted this link several times lately, can't remember if in response to you or not, but here is a link to a GREAT tutorial on how "Kettering" ignition systems work...

http://www.cleancomputes.com/Cub/Blue%20Ribbon%20Service%20Manuals/FOS-20%20Chapter%206-Ignition%20Circuits/index.html
FOS20
 
They can run warm, but usually not so hot you cant keep your hand on them. However, if theres no normal on off duty cycling (say engine is off but ign left on) where the points are opening and closing when engine is running THE COIL CAN GET TOO HOT. True, they need to have the proper gap and obviously must open and close before the coil can fire.

On the coils HV output terminal when the points open voltage begins to rise and normally (if coil wire and plug wires and plugs all in place) BUT IF THERES NO COIL WIRE ATATCHED VOLTAGE RISES MUCH HIGHER AND CAN ARC ELSEWHERE LIKE THE COIL SURFACE. Its NOT good for coils to fire them with no coil wire and plugs and plug wires and/or other made gaps cuz the voltage rises too high and a HV breakdown can take place and ruin insulation.

To fire the coil, the LV primary must first conduct current via closed points and then they must break open to interrupt current flow

Youre gettin there

John T
 
Same thing I observe here Bob, I post and post info but they dont seem to look at or get it and keep asking the same questions??? Maybe instead of my posting a link I need to copy n paste the entire article to spoon feed it? No sense in reinventing the wheel each time these same questions are asked I thought but ????? lol

I subscribe to the old Bible philosophy about where if you give a man a fish you feed him a meal, but if you teach him to fish you feed him for life. Some are just lookin for the quick meal ya reckon???

John T Fellow sparky
 

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