Hey everyone.

I've got an 1985 f1590. From what i've gathered, I noticed that my truck DID have a duraspark ignition system. However, even though the plugs that plug into that one box thing are there, the box is not.

The truck starts up when you turn the key, but.. what did they do to it?

Should I keep it how it is now? Or should I go back to the duraspark ignition?

What would I need to change it back to the duraspark ignition?

 

Your truck was likely factory equipped with the "TFI" system. That was pretty common on the 84+ 6 cyl and 85+ 302 EFI. The DS plugs were on all 86 & older trucks, as some 86 models still used that system.
Does your current distributor have a box on the side with 4-5 wires? If so, that's the TFI system.
Swapping to a DS2 system requires a dist, coil, module, plug wires (mabye just the coil wire) and the engine harness. Once those are gathered up, it's all plug-n-play.

 

My truck does not have a box on the side of the distributor with any wires...

So, it's not a TFI system...

 

Being a 1985 model, it would NOT have had the Duraspark ignition, unless someone had changed it over. Your truck *should* have the TFI/EEC system, but someone may have changed it to a points ignition, or maybe even a Pertronics ignition. Being as your truck is getting on TWENTY FIVE (25) years old, anything could have been done to it by now.

Stock, your 1985 I6 engine would have come with the TFI ignition system, EEC-IV computer, and a "feedback" carburetor. This replaced the Duraspark II ignition starting in 1984 on the 300 and 302 engines; the 351 and 460 engines still used the Duraspark ignition. (This is why the same plugs are used for both systems, so either harness could be plugged into the truck's main harness.)

Look closely. Do you have ANY wires leading to the distributor? Do you see a thin, rectangular shaped ignition module bolted to the side of the distributor?

Do you have a square or round coil?

What carburetor are you running? Do you have a vacuum advance? Look for a vacuum hose going from the distributor to the carburetor.

 

At the bottom of my distributor, there is a box with 7-9 wires coming out of it that plugs into the bottom of it.

Thin rectangular ignition module? There could be, but I didn't really see it..

What carb. do I have? No idea. Vacuum advance? What's that? Look for a vacuum hose from the distributor to the carburetor...

*goes and looks*

 

No hose going to the distributor to the carb...

However, the carb is missing a few hoses...

So it could be a missing one.

 

That sounds like your stock TFI ignition module. It is bolted to the side of the distributor and is controlled by the EEC-IV computer. (The larger Duraspark ignition module is square and mounted on the driver's side inner fender.)

But, to be sure, look on your distributor itself. Do you see a vacuum advance canister in the front with a nipple sticking out of it, like where a vacuum hose *would* attach to?

Do you have a square or cylinder shaped coil?

EDIT:
I took the liberty of doing a search on all of your past threads, and saw your video and engine pics. You do have a TFI ignition, not a Duraspark. I also see the MAP sensor, O2 sensor, and EEC code reader (big red plug on the passenger's side) - all indicative of the infamous TFI/EEC system. But it appears as if someone went and "messed around" with your ignition system and carburetor. This is a BIG NO-NO when you have the TFI and EEC-IV engine control. Unlike older systems, the EEC system you have all works together. The carburetor, ignition system, timing, and emissions all send signals to the EEC computer on your truck. The computer then makes adjustments from all of these signals to make your truck run efficiently. If you disable ANY of these sytems, the computer will go into "limp" mode, which will, in turn, affect engine performance and efficiency.

You are gonna have to do some research and post some more detailed engine pics so that we can figure out what you are working with first, before we can begin to correct the problems you may have. Don't worry, I have a 1985 F150 as well, and I was in the same boat you are in now just a couple of years ago.

But hey, at least it runs, right?

 

What exactly should I take pictures of?

I can make videos and pictures, I just need to know what exactly of.

XD

I could use all the help and knowledge I could get.

Thanks so much guys.

 

Coil... Coil... Coil...

Are you talking about the thing that I plug the spark plug wires into? (I think you call that the distributor cap, though)

But, if that's what it is, it's a circle.

Now, if it's that one box thing where the middle spark plug wire plugs from the distributor cap to the square box thing, it's a square.

Or.. is it something else?

 

That's it, the middle wire is the coil wire.

 

You have a square coil, which is the stock TFI ignition coil. (The Duraspark coil would have been shaped like a cylinder.)

Again, your truck does NOT have the Duraspark ignition. Keep in mind that the TFI ignition/EEC-IV computer system was only used on carburetors for a couple of years, so most people, including most mechanics, do not really know much about these systems. They were more common on the EFI vehicles. The "feedback" carburetor is expensive and a pain all by itself, and all the associated sensors needed to keep this system working correctly can be very expensive, and you will probably get laughed at it if you ask an auto parts store or even the Ford dealer to pull the codes for you. This is why a lot of people who are "blessed" to have a 1984 or 1985 model, including myself, convert to the older Duraspark ignition system.

First question: Where do you live, and does your state have emissions testing? In some states, it is illegal to tamper with your vehicles operating systems, and that includes converting to the Duraspark ignition. If you have emission testing, the only option for you would be to fix what your truck came with originally. If you keep what you have, either by choice or by law, you can ONLY use your stock feedback carburetor, and hardly any performance parts will be compatible. Depending on the condition of your truck, and if you are satisfied with what you have, you still may be better off just fixing the "feedback" carburetor and TFI/EEC-IV system you currently have.

**For example, from your pictures, I can see that the wires on your O2 sensor (on your exhaust manifiold) have been cut off, AND your MAP sensor (located on your passenger's side fender) wires have also been cut off. These two sensors will have to be hooked up and working, for your truck to run correctly. Also, your EVAP controls have been removed from your carburetor, and that also has to be dealt with.

Second question: Do you want to modify your truck for better performance? Assuming you do not have emissions testing, you have a few more options. If you wish to modify your vehicle for better performance, you *cannot* use the system you have; you will have to switch to a stand-alone ignition system, like the Duraspark II (DS2), or look to the aftermarket, like MSD, Mallory, Accel, etc.

**For example, the stock "feedback" carburetor on your truck will never run correctly without the EEC computer and stock ignition system in working order. From the other side of the equation, if you would like to go to a 4 barrel carburetor, the stock electronic controls currently on your truck will not be able to "read" what the carburetor is doing, so the EEC computer will lock the timing, which retards performance and emissions will suffer. And that is why you will have to change the ignition system. Get it?

Because I can see you are learning, let's stop here for now. Answer the questions above, and then we will go from there.

 

L85 is spot on.

I will add one additional question, though.
In looking at the various pics/vids you have posted, it would appear as though the carb doesn't have a lot of wiring going to it. Can you get a close up shot of the carb, front and both sides, and post them.
At a minimum, please examine the carb. How many wires does it have going to it?

 

I too have a 1985 Ford F150, with the TFI ignition system. Mine is still intact and for the most part original. If you need me to take some pictures for reference, just contact me.

 

Question One: I live in North Carolina, and I believe that a vehicle older than 1996 does not need an emissions test in North Carolina. Am I sure about that, I am not. Right now, I just want to fix what is currently on my truck, not add to it... Well, not right now. And how do you know which wires are the O2 and MAP sensor have been cut off? And what do they both do?

Question Two: Right now, I'm not going to add any performance parts... However, if most people switch to the DS2 ignition, I might have to do that. However, what would it take to do that?


So, I DO have a "feedback" carburetor? And how will I get the EEC computer and stock ignition system in working order?

And does anyone know if North Carolina made it illegal to switch to the DS2 ignition?


Rogue_Wulff: After I post this, I will go out and take pictures of both sides of the carb. I also will take pictures of the square thing and the distributor, just to make sure i'm not mis-informing you.

I'm also going to make a video and post it on youtube with me pointing and asking questions about certain things.

So, headed outside!

 

Alright, so, we could have a problem.

That coil wire that goes from the distributor to that one thing? Well, the white plug that plugs into it is rectangular, but the actual thing itself is a cylinder.

(Yeah, I know. I'm a noob, but the thing did look square from a look. But after going and LOOKING at it. It's a cylinder)

Oh, and another question..

Where is my EEC computer?