Ford TFI Ignition - Points/Trigger Hybrid

jsoluna

Member
Ok so I've obsessed over the ignition system on my 8n and I've determined that I'm not entirely against going electronic with the sad state of points manufacturing quality control.

I have some experience with the Ford TFI systems used in late 80s and early 90s trucks and cars. They are dirt simple to wire and do not require a hall effect sensor to be integrated. This means the stock points system can be retained, and that the points just act as a trigger for the module. Increases longevity, decreases wear and maintenance.

They're cheap, easy to find at any parts store, and if they fail in the field you still have your mechanical breaker system in place. Only modification is see being necessary is to get a wire lead off the grounded side of the square coil. Everything else remains stock.

I did not see where anyone has done this yet. Thoughts?
 
I use a GM 4 pin HEI module on my 51 8N. No condenser. N.O.S. Blue Streak points. Of course the GM module switches off (makes spark) when input goes low, so it does require an inverter for the signal from the points. A 2N2222 transistor and a 4.7kΩ resistor does that job. The points only see ~3mA current when closed, and that current is purely resistive, so there will never be any spark or arc at the points. Eventually they will wear out mechanically, but never electrically.

My understanding is the Ford TFI makes spark when input goes high so it would not require the inverter. However I used the GM module as I had one on hand at the time. Tractor left me stranded in the field at the far end of the farm. I thought it was the condenser that had failed. I did not have a spare condenser. Walked back here to the shop and used parts I had on hand to make up a "kit" I could install in the field. Was middle of the night so no parts stores open in town. Took the kit and needed tools to do the installation and walked back to the tractor at first light the next morning. 10 minutes later was back pulling the drag around in the field.

Of course there is still the problem of when letting the tractor sit too long in humid conditions sometimes the points will need to be cleaned of whatever insulative film develops on them, so is not a perfect solution, but that has only happened once since I installed the "kit" and that was when I was sick for a month. Tractor is parked under a shed, but would not matter as when humidity is high everything gets rusty here even if it is in climate controlled space.
 
(quoted from post at 07:13:04 08/16/19) Ok so I've obsessed over the ignition system on my 8n and I've determined that I'm not entirely against going electronic with the sad state of points manufacturing quality control.

I have some experience with the Ford TFI systems used in late 80s and early 90s trucks and cars. They are dirt simple to wire and do not require a hall effect sensor to be integrated. This means the stock points system can be retained, and that the points just act as a trigger for the module. Increases longevity, decreases wear and maintenance.

They're cheap, easy to find at any parts store, and if they fail in the field you still have your mechanical breaker system in place. Only modification is see being necessary is to get a wire lead off the grounded side of the square coil. Everything else remains stock.

I did not see where anyone has done this yet. Thoughts?
ill not solve any thing. Likely make things worse. One major problem with points in seldom used tractors is the oxidation that forms and acts as an insulator. That becomes more of a problem when the current being switched is a thousand times smaller in the scheme being proposed! The usual 4 amps will help burn thru the oxidation when & if you can start it, but a few milliamperes will not. If you want to solve points problems, the FIRST step is to get rid of points. As an aside, I don't think Ford ever used a points operated SS ignition system.
 

You bring up a good point I hadn't considered. Oxidation vs pitting/wear is certainly something to be aware of.

Not trying to overcomplicate an otherwise functional system - just see opportunity for making the tractor less troublesome to maintain. If I can come by a reliable source of decent points sets, I don't mind annual maintenance on them.

I expect the tractor to be used semi regularly but it does get super humid here at various times of the year.
 
jsoluna,I did not see where anyone has done this yet. Thoughts?

I have been triggering a MSD5 box for years using points with out problems that have been mentioned. It is not a front mount tho.
 
If a person is going to retain points, I can see using HEI, but a worse could not be made than the Ford TFI module!
 
(quoted from post at 16:03:51 08/16/19) If a person is going to retain points, I can see using HEI, but a worse could not be made than the Ford TFI module!

I owned a number of Ford Thunderbird Turbo Coupes with the EEC-IV/TFI ignition system and still have one. There is a reason the TFI modules are cheap - lifespan of a June bug. :roll:

TOH
 

The faults of the Ford TFI were related to heat dissipation/location. I've owned several and on ever one that was distributor mounted I relocated and added a heatsink. Never had issues after that.
 
Could never understand why Ford put a heat sensitive component on one of the hottest parts on the engine.

I think what I'll do is just have this as a cool tinkering project on the back burner.

Hopefully these Echlin points hold up for a while (and they should, everything is timed, gapped, and gasketed/cleaned properly). In the meantime I'll probably find a spare distributor and coil and start messing around with it.
 
I did mid 70's HEI with Ford 2.3 Reluctor and Pickup.

The coil, mount and heat sink are from 1998 - 20?? Chevy truck

ei%20distsm.jpg

coilsm.jpg


Kevin in MN
 
(quoted from post at 20:20:21 08/16/19) Could never understand why Ford put a heat sensitive component on one of the hottest parts on the engine.

Making a bad engineering decision is one thing. Sticking with it for almost two decades once you clearly know better and continuing to foist it on your customers is another.

TOH
 
(quoted from post at 07:25:00 08/17/19) I did mid 70's HEI with Ford 2.3 Reluctor and Pickup.

The coil, mount and heat sink are from 1998 - 20?? Chevy truck

That looks worthy of a How-To article or even a kit to sell.
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top