I have an 87 F150 with a straight six and a 4 speed. I've owned the truck since I was in high school and its time to start fixing it up. Everything works well on it, but i'm a bit concerned about the duraspark ignition system in it. As I'm sure most of you know, you can buy the distributor, the coil and module, but as far as i know you cant get the wiring harness that connects all of it together. I have another 87 with a carbureted 460 in it. That same harness went bad and I fixed it by installing a Proform HEI distributor and just deleted all that wiring and extra parts. A lot fewer parts and it works awesome. The F150 is a bit different because its an EFI motor and every HEI style distributor i've looked at are vaccuum advanced, so don't think it would work so I thought I would ask all of you. Everything still works, but id rather address this before it becomes an issue on the freeway since the truck is 30 years old. Do you guys just build your own wiring harness? Do you swap out the distributor for a different system? I'm close for 40 and have the truck since I was a teen, and its not going anywhere any time soon. Any input would be appreciated.

P.S. I know that Painless wiring offers a harness for it, but I've used some of their stuff before on other projects and have not been impressed. Their stuff seemed very cheap and not very durable.

 

So clarify, does the distributor you have now have the ignition module on the side of the distributor or a is the ignition module a separate larger box probably on the firewall?

 

The ignition module sits just in front of the distributor, on the driver side of the engine. The Module is in front of the motor mount, the distributor just aft. I added a picture below.

 

But the module is attached directly to the distributor, correct? And the distributor DOESN"T have a vacuum advance, correct?

 

I just edited that last post to add a picture. No, it does not have a vacuum advance and isn't really directly attached to it, its sitting right next to it. To adjust timing there a plug in the harness you have to pull with the engine off

 

I can't tell for sure from the picture, but I think you have the normal distributor for a 1987 through 1991 6 cylinder engine. What do you want to do, move the ignition module away from the distributor like the 1992 through 1996 6 cylinder engines have?

 

Sorry about the picture, its pitch black dark out here and raining lol. I'll take a better one tomorrow when its light haha. I would like to convert to an HEI distributor like I did with the 460 ( the wiring harness that goes from the module to the ignition coil to the dist. went bad and left me stranded on the freeway...good times), but I don't think the HEI style distributors work with an EFI motor. I'm just curious to see what the other folks do with theirs. I had to make the conversion on the 460 because that harness isn't available anymore so customized it and deleted it all. Can this be done with the I6? Like I said, everything still works, i'm just thinking ahead.

 

The distributor in there is considered High Energy as far as I know. You have to have a certain style distributor with ignition module for EFI, you are correct. You wouldn't gain anything by changing distributors, unless you moved the ignition module off the distributor like the 1992 -1996 models are. The only advantage there would be the ignition module not getting hot and going dead eventually.

 

It appears you have TFI ignition / EEC IV.

 

can you still buy the wiring that connects all of that together? If so, i'll just leave it where it is. That's where I went wrong with the 460. The wiring that goes between the distributor, the ignition coil and the module (which was mounted on the driver's side inner fender well) had some kind of built in voltage regulator that was tied into the harness. When that went bad, the distributor wouldn't work properly and the truck wouldn't run. When you go to the parts store to inquire about it, you get a deer in the headlights look. I considered just building one, but the plugs on that go to the components arent available anymore either, so you'd have to leave a couple inches of old wiring attached to the plugs and then solder/butt-connector new wiring to them and hope it works. The HEI distributor was great because they have a built in coil and no need for the modulator. Once installed, the Ignition coil, the ignition module, and all that old wore out wiring that I couldn't replace went into the trash. I'll go out tomorrow and take a few pictures of the engine of that truck and post them on here so you can see. It really simplified the engine and eliminated that wiring. In regards to the the straight six, I wanted to do something similar in case I ran into the same problem. Is that wiring still available? I don't like buying new vehicles (I have no debt and hate payments) so I want to make my old stuff work for as long as possible.

 

As far as buying that wiring NEW I doubt it unless some aftermarket company made it. I would say about all you could do is some searching.

 

Exactly, that's why I was wondering if anyone else had made the switch to something else on these EFI models. There wasn't much choice with the 460. With the HEI all you have to do is connect the thing to your battery in whatever way makes you happy and you're done. All that wiring and all those parts go into the garbage, but like I said, the ones ive dealt with are for carbureted models. I'm trying to see if any such thing exists for the EFI models.

 

See if you can find a new OEM harness. Or get one from the scrappy. Meanwhile, inspect what you have, relieve stress on any wire, tape or zip tie stuff up if need be. Hold a good spare in reserve.

Then, as they say in Massachusetts, "Drive off that bridge when you come to it". Don't go fubar your wiring etc if your truck is running right.

Swerving suggestion.

 

If you get the specific Ford part number of the individual piece of wiring there are places that kind of specialize in new old stock NOS parts. You could get the part numbers from your Ford dealer. This would be one option. I'm not clear, is your wiring bad or are you just thinking it may get bad?

 

That's sound advice. I'll see if I can find an OEM one and just keep it in reserve. If I study it long enough i'm sure I could just make one myself. While I certainly agree that its foolish to mess with it if its still working, the one in my '87 460 worked perfectly until it didn't lol. It wasn't a slow build up to failure either. When it went bad I went from going 70 mph to zero on I-5 . Getting it fixed was interesting experience because once i finally got the truck home, I was convinced the coil was bad, so I bought a new one and it still wouldn't start. Then I replaced the module - nada- finally the distributor --- still wouldn't work. When it sat for a few hours and you cranked it, it would start and run for a few brief seconds and then instantly die and you couldn't get it running again. When I finally pulled my head out of my read end and got the multimeter out and started checking the readings in the wiring harness while my friend cranked the ignition I got all kinds of weird readings...it was a year ago so I can't recall the numbers but I remember they weren't right and I concluded the harness and built it voltage regulator had gone bad. Owning old vehicles is always an adventure! haha. ----Old parts work fine until they don't lol.