question on how to adjust/test coils

[LittleTimmy52]

one of my coils are weak, i know because when starting if the commutator is rotated such that one of the coils is buzzing before i crank it, sometimes i hear a strong buzz other times its weaker, and sometimes its real strong, I don't know which coil(s) are making the weaker noise nor do I have access to a tester, how do I get them all going about the same to get consistent spark? this might explain how the car seems off in high gear.

[speedytinc]

Have them tested/adjusted on an ECCT. Coil tune is critical for a good running T.
If you cant find someone with a tester, consider an aftermarket distributor.

[Jerry VanOoteghem]

You can't really judge coil performance by sound. How does the car run? Any misfires?

[TXGOAT2]

The sound a coil makes does not necessarily indicate its condition. I adjusted all 4 of my coils to sound about the same and the car would barely run. The only way to correctly adjust the KW type coils is to use an HCCT or ECCT. All 4 coils can deliver a strong spark and still be out of adjustment. The very early type coils can be adjusted "by ear", but not the later type. One reason the early coils were adjusted by ear is that they had no better way of doing it.

[Dan McEachern]

Suggest you contact one of the coil folks listed on the forum suppliers page. Best to send them off and have them adjusted/ rebuilt for best results.

https://www.mtfca.com/model-t-ford-suppliers/

[LittleTimmy52]

You can't really judge coil performance by sound. How does the car run? Any misfires?

I mean in high gear something feels off, I can't put a finger on it but the t is telling me something is not quite right. Low and reverse are boo noisy to tell anything based off gut feeling and idle is fine. Just in high it feels off. It might be me being off my rocker but it doesn't feel right.

[LittleTimmy52]

I mean the weaker one sounds notably quieter and grobbles not buzzes like the others, y'all said noise isn't big an indicator but with it seeming off in high gear plus the odd sounding coil(s) shouldn't that mean something?

[speedytinc]

Regarding sound. I have adjusted enough coils on an ECCT. During the process, one can hear differences that coincide with a tune improving.
The final very good passing coil has a definite, clear, loud clack, as opposed to a weak buzzing. There is no way I could get that sound & performance without aid of electronic equipment. There are two many adjustment variables with the points.
Having a good running T on a coil & timer system takes a real commitment.
Those that don't have that commitment can still enjoy other aspects of T driving with a distributor.
I learned this getting my timer & coil system to its optimum ignition performance.

[Dan Hatch]

Start by reading the Ford Service Manual, then move on to the club video on coils.
Then spend several hundred dollars getting the right tools to adjust coils. Or send them to a coil person and get them repaired. Dan

[TXGOAT2]

Inspecting your spark plugs can tell you a lot about how the different cylinders are performing. What kind of timer do you have? Have you cleaned or lubricated it recently? Is your fuel filter clean? What about the carburetor adjustment? Have you tried adjusting the carburetor while driving down the road to see if performance improves? Is the choke releasing fully? You may have bad points, a bad condenser, a coil with poor adjustment, a timer issue, a wiring issue, a spark plug issue, or a fuel/air issue. (Among others).

[J1MGOLDEN]

Open up one of those coils and examine the capacitor.

You will find two rolls of tin foil with two rolls of wax paper between them.

The capacitor is attached to the two coil points, and they have to be open for measurements.

If the capacitor is shorted, rather than open, there will be no sparks at the points or the spark plug.

If the capacitor is open the points will work for a short time and then weld themselves shut.

The best solution is to have the coils rebuilt by one of two professional rebuilders that I can recommend!

[TXGOAT2]

It would be a good idea to determine what the problem is before trying to remedy it.

[Jerry VanOoteghem]

Suggest you contact one of the coil folks listed on the forum suppliers page. Best to send them off and have them adjusted/ rebuilt for best results.

https://www.mtfca.com/model-t-ford-suppliers/

The best advice so far...

Get a known good set, (and a spare coil), and remove that variable from your problem solving process.

[J1MGOLDEN]

Put another way, "Has anyone ever replaced the points on an original coil and found the capacitor was still good?"

I am kind of new yet, I have only been testing coils for 45 years, and I have a Capacitor Tester, an ECCT with the Computer Program, a StroboSpark, A New and Old Stafford Coil Tester, and two restored HCCTs, but I have never found an original coil with a good capacitor!

[JTT3]

Best bang for the buck are rebuilt coils by a competent professional rebuilder. It’s the only way your T will be in normal sinus rhythm. You’d be surprised how much better your T will run, even if it’s a tired engine. Like Dan said paraphrased, you could buy about $800 + of equipment plus a lot of learning the technique & still not be competent or spend around $300 + or- for a set of 5 coils rebuilt by someone that knows what they’re doing. I’m speaking from experience. I have a HCCT, 2 strobo sparks and an ECCT with computer upgrade. Yes I’m a glutton for punishment. I finally realized that it wasn’t the equipment but the technician. I fired me & send them off to my go to guy. Best John

[Original Smith]

Get Ron Patterson to rebuild them. They will last forever.

[J1MGOLDEN]

Ron and John have been the "best of friends" for many years.

That is about the same with Ron and me.

Early in production, Ron suggested I should get a StroboSpark and I bought one.

A few weeks later, Ron asked me how I liked it.

I told him I was going to send my unit back, as it does not seem to work right and always tells me the capacitor is bad.

Ron told me he assisted John in the development and got one in the early days of sales.

He always used the StroboSpark to test each coil sent for repair to determine if it was worth rebuilding.

At that time, he had tested and rebuilt 2,500 coils and found about 40 had a good capacitor.

My unit still works fine now!

[AndyClary]

Another recommendation to send them out. The turn around time usually isn’t too bad. Simply put you cannot adjust a coil without a tester.


Andy

[J1MGOLDEN]

Another good plan is to keep a spare restored set, just in case you or one of your friends need some or one.

Some T owners carry one or two, a set of spark plugs, a spare timer and a spare carburetor., along with the spare tire and often a new tube.

[Moxie26]

.. Extra Restored coils should be kept in a secure, protected environment such as a locked coil box or packaged in cardboard to protect the point set on top of coils from any pressure or physical damage to offset coil calibration. Ignition coils that are kept under the seat in a car are subject to being out of proper settings.

[Drobnock]

Two cents of unwanted comment.

Over the years I have set and been satisified with adjusting colis as needed with the traditional "Buzz Box Tester." If you have the funds then purchase the electronic tools.

Unless there has been a total up grade of the Coil/mechanical timer for ignition the adjustments of the induction coil needs to be checked every 500 of so miles or when started for the new driving season.

Remember it is a Ford, and the Ford has been designated as "Fix or repair daily." And possibily this originated with those not familiar with the early Fords, esp the Model T.

[J1MGOLDEN]

That device will tell you when a coil is bad if you get no sparks.

I cannot tell you the coil has a good capacitor!

There is no capacitor tester on this device.

If the capacitor was not important, the coil would not have one!

Henry was not one to hang on the bells and whistles on his T parts.

[Drobnock]

That device will tell you when a coil is bad if you get no sparks.

I cannot tell you the coil has a good capacitor!

There is no capacitor tester on this device.

If the capacitor was not important, the coil would not have one!

Henry was not one to hang on the bells and whistles on his T parts.

No argument on the importance of the capaciator in an induction coil. Henry had nothing to do with the development of the induction coil and the use of the capaciator. Matter fact cars of the period used similar coils, For a good read on the induction coil find a copy of:

Generally, and I can be wrong, a fat spark at the coil points indicate an open cap.

Foot Note: Circa 1906 - The early Rolls-Royce cars had used a trembler coil to produce the spark with a magneto as an optional extra which soon became standard - the instruction was to start the engine on the trembler/battery and then switch to magneto. Part of an Ignition system for an early Rolls-Royce:

[John Codman]

It would be a good idea to determine what the problem is before trying to remedy it.

I sure agree with this.

[Chris Barker]

They say that the two best days in a boat owner's life are the day he (she) buys it, and the day he (she) sells it.

The two best days in a Model T owner's life are the day he (she) buys it, and the first time he (she) drives it with a properly adjusted set of coils.

Anyone who disagrees has yet to experience day 2.

[Charlie B in N.J.]

I was a buzz box guy. Even built and sold a few on E Bay. This was years ago and I was taught a lesson when a friend who lives not far from me contacted me through the Forum. He had an HCCT and did coils for the local club. I had rebuilt mine, ( cap, points etc ) and he came over and set them up for me. My car started, dead cold, on the hand crank after we reinstalled them. Brother I was sold.

[TXGOAT2]

A buzz box is much better than trying to adjust coils "by ear". But an HCCT is FAR BETTER, and an ECCT is best.

[J1MGOLDEN]

Perhaps another trade secret.

You can slowly increase the cranking speed of a HCCT that has two meters and watch the AC Volt Meter reading increase when you increase the speed until the sparks happen around the spark ring.

That lets the spark happen at a slightly different voltage level for each coil.

That spark also happens with the piston at a slightly different level and can cause a slightly different power level on the running engine that is not providing quite such as possible smooth an operation.

The ECCT sets all the coils to make sparks happen at exactly the same voltage level and that does provide a smoother running engine with a little more power.