Just play with it. You will find the sweet spot. You just don't want to get it so fast that is bangs into drive if you have a automatic.

 

I remember someone was testing them but I dont know how it was done?
Now what you should know when the parts jockey knew how to test them it was only a "bench test" and they would always pass.
Why is this? could it be it is not in the heat of the engine bay? Maybe because it was not under load to fail? Maybe both or something else?

We are finding that they also dont just stop to make spark when they go bad but can cause other problems of poor running and the bench testing would not show that just if it works or not.
They are cheap enough, buy top of the line one I run a NAPA without problems, and if that did not fix the problem you now have a spare for when the box does fail.

I said I run a NAPA top of the line box, I only replaced the one on the truck because it was leaking the potting down the fender and onto my garage floor making a mess.
Being it was still working I keep it as a spare if needed.
Dave ----

 

I see you have spaced the box off the fender well for air flow but have you given it any thought how that dirty box is holding in ay heat?
Mirror polished is not good either as it can trap heat in like chrome does.
Now do you think if it was painted flat black it would dissipate heat the best?
Could that be why engines are painted black, think GM did black engines in the 80's?
Dave ----

 

You can test the ignition module. For what it's worth, I like the "vintage" look of your DS2 box.
If you haven't installed the distributor yet, connected the 3 wire harness to the distributor. Connect the Coil to the horse shoe connector. From your photos it looks like your ignition module is connected.
You will need to ground the distributor, just use jumper cables. The coil doesn't need to be grounded.
Spin the distributor gear and watch the output of the coil wire. Do you have a spark tester?

Jim

 

I actually have 2 of those vintage branded Duraspark modules - apparently they both work but I want to be sure. I have a spark tester but I may just throw plugs in the ends of the wires and spin the rotor by hand once it’s all connected. Then watch to see if the plugs arc against the engine.

 

I think I’ll do this. At least I’ll know I have a good one brand new and I can remove that from the troubleshooting equation if I run into any spark issues.

 

Let me be the first to worn you!
New parts do not mean good parts as today new parts are bad out of the box.
This can cause all kind of problems as you installed the new part and think all should be good and it has not fixed the problem so now you go replacing other parts.
Now what if 1 of them other parts are also bad, now you have 2 bad parts and you go replacing even more parts.

That is why we try and walk people through on how to test the system before shooting the parts cannon at it.
Now like the ICM or TFI because they are cheap and somewhat easy to change out and what we see most of the time we say replace them before a lot of testing.
If that does not fix the problem we then get into the testing to find just where the problem is.
Depending on how the truck stopped working we may do the testing first.

The other thing with parts is the parts stores will always sell you the cheapest because they done know if you checked with other brand stores and know the price.
Now you get what you pay for and on some parts that is ok but we have found for ICM, TFI and starter solenoids it is best to ask for top of the line as they last longer when in service.
So keep that all in mind with new parts.
Dave ----

 

When you get all the connections made, check Coil Positive, with the key ON, distributor not turning.
It should be 6 to 8 volts. Yours might be higher if you have the extra 3rd wire, Bypassing the resistor wire.
You can see the lump in the harness in your photo (post 14 - first photo), just remove the tape and look.

Jim

 

One of the wires from the AC system fed a kicker that would bump up the idle while the AC was on. You wont need it. Just bump your idle up a hair come summer time. The other looks like a temp sensor that fed the ecm. It is not needed either

 

the coil on an 86 tfi should be a full 12v

 

Agreed, and it is currently full voltage, which is what creates the problem when going back to a DS2 system that needs a coil voltage considerably lower.

Jim

 

yes, or the OP can install a resistor or an HEI. 👍

 

Sorry I’m just getting back to this - life got in the way last week. From what I’ve read, it’s easy to burn out the DSII coil if the key on voltage is too high. By using an ignition harness, ignition, module, and dizzy from an 83, I was hoping I found myself a plug and play option. Plugging in the harness should allow the ignition system to now use the factory resistor wire that was bypassed in the TFI system harness, correct? I don’t need to add any ballast resistors like I’ve read on some forums, correct? It was my understanding that a ballast resistor only had to be added if you jacked up the harness or did some DIY electrical work arounds.

 

Yes, yes and yes. You can verify the voltage after you get it running. It will not instantly go up in smoke if it does not have the resistor. So you can test it afterward.

 

https://www.ford-trucks.com/forums/1...l#post21672187

In the above link you will see a photo of the splice in question. His truck is also a computer controlled EEC -IV Six cylinder. Notice his splice is in standard DS2 configuration.

You will not know the answer until you actually look at the splice on your truck.

Running full voltage on a DS2 will cause the coil and the ignition module to run hot. But you have a spare module already, you could just carry spare parts.

A lot of these trucks have been converted with the "plug and play" concept. Hoping for good results without checking the coil positive voltage after the conversion.

Jim