Two days ago, I converted my '84 F150, With a 300 I6, 4 Speed Transmission, and Four Wheel Drive over to the Duraspark II ignition system. Here's how I did it:
First things first. Why convert to the older Duraspark II (DSII) ignition system?
Simple. the DSII system is a much more simple and reliable system than the ignition system found on F-Series trucks made from '84-'86. It doesn't require tons of wires, a computer, or that terrible electronic feedback carburetor that never seems to work right. The system also features an automatic spark retard while cranking to reduce the load applied to the starter motor.
What you'll need:
To convert your truck to the DSII system, you'll need a few parts.
The DSII distributor has a single vacuum advance that takes 3/16" hose.
The DSII ignition module can be identified by the blue grommet on the bottom of the module. It sometimes says "Duraspark II" on the front. The module has two plugs coming out of the bottom of the unit. If you grab one from a junk yard, be sure to take it to a parts store and have it tested before you install it. I pulled one off of a '78, and one off of an '82 at the junk yard. Only the one from the '78 was good.
Almost any coil can be used with this system, but for ease of installation and maintenance, I used the stock coil out of an '82 F150.
The wiring harness is quite simple. Typically, on one end, it has three plugs, one for the module, two that plug into the truck using the plugs that are already there. It has a crescent shape adapter for the coil, plug ins for the water temp. and oil pressure senders, and finally a plug for the distributor. For some reason, mine (I pulled it off of an '82) has an extra plug. I haven't quite figured out its purpose, but as soon as I do, I'll post it on here.
Where to find the parts.
Although Ford began using the Duraspark system in 1973, the DSII system can be found on virtually all F-Series trucks made from (if I'm not mistaken) 1976-1983, however, if you are installing the system on an inline six, then obviously you have to use a distributor that is compatible with that motor.
Generally, you have three options in your quest to obtain these parts.
1. Junk Yard: Usually, you can find most all the parts that you need for the conversion at your local junk yard. I managed to pick up the distributor, wiring harness, coil, 2 modules, pedal pads, and a glove box insert for $79.16. Pretty good price when you consider that a distributor alone will cost you $50 at Advance Auto Parts.
2. Autozone, O'Reilly's, Napa, Advance, etc.: All the parts that you need can be found at your local parts store, with the exception of the wiring harness. The wiring harness is particularly hard to find, and if you do manage to find one for sale, it'll probably be pretty expensive. Now, if you decide to go this route, you will be getting new parts, but be aware that not all the parts that you can buy from these places are quality components. Many people have gone through multiple ignition modules before getting one that was good, only to have it fail on them months later.
3. Ford/Motorcraft Parts: If you do want new, quality parts, then you can always order them directly from Ford/Motorcraft. However, be aware that while these are good, new parts and not remanufactured, their prices are obscenely high.
Junk Yard. Unless you MUST have brand new parts, I would go to the junk yard. You can get original, Ford/Motorcraft parts, AND a wiring harness, for a fraction of the cost of just a new distributor ordered direct from Ford.
To start off, your engine bay may look something like this (with, or without the mud.)
The first thing that I did was disconnect the battery. Then, I installed the ignition module on the inner driver's side fender. I have heard that some people stack rubber washers between the module and the fender to increase the airflow underneath the module and help keep the module cool. I would have done this, but didn't have any rubber washers on hand.
Then, I removed my spark plug wires, and the distributor cap. (Note that the wire that goes from the distributor to the coil on the '84-'86 TFI ignition is not compatible with the DSII coil. You'll need a set of spark plug wires from a '76-'83.)
Then, I removed my old coil. If you have a bracket like mine, there should be four small bolts on the corners of the coil bracket on the side facing the engine. Be patient, as these took me a while to get off.
Then, I unplugged the distributor from the wiring harness, removed the distributor hold-down bolt and clamp, and pulled the distributor out of the engine.
You may want to stuff a paper towel, shop towel, or rag into the hole in the engine to keep dirt, dust, etc. from getting in there.
After that, I installed my coil. I used two hose clamps, and secured it to the old coil bracket until I can find a better way to secure it.
After that, I plugged in the new wiring harness to the module, and into the truck's harness that comes out of the firewall. The plugs are pretty easy to match up. Now that I think about it, I'll post another picture of the plugs and exactly which plug goes where, in an attempt to further simplify the process.
After that, I installed my distributor and hold down clamp. I did decide to go ahead and get a new cap and a new rotor. Didn't cost too much. (forgive the greasy fingerprints on the new dizzy cap) Then, I put on the new spark plug wires.
Then, I plugged up the new wiring harness, and tinkered with the distributor (advance/retard) until the truck would start. Once it was idling, I went looking for the vacuum port on the carb to plug the vacuum advance from the distributor to. You're going to want to look for the port on the carb (usually on the passenger side) that pulls no vacuum at idle, but starts pulling vacuum as soon as you open the throttle, and plug in the vacuum advance to that port. On my carb, it was this one:
Finally, I disconnected the vacuum advance from the distributor, and timed the ignition, reconnected the vacuum advance and I was done. Total elapsed time: About 2 hours, with a lunch break in the middle. Overall, it was an amazingly easy conversion.
Now, you may notice that the old wires, harness, etc., is still laying in the truck. I didn't have time until today to remove the extra wires, etc. Unfortunately, my sister needed the camera for school today, so I'll make sure and post pictures of what I removed, along with pics of the cleaned up engine bay tomorrow, and continue the write-up with what can be removed, and how to do it when I post the pictures.
Let me know if you guys have any questions, or if you have anything to add. Also, if you guys can see any mistakes that I've made, please let me know. Thanks, guys!
Nice write up. It's worth noting that a non-feedback carb is also needed to *properly* complete this job, as the computer controls both the ignition and carb. Replacing only the carb or distributor/ignition system is only going to give part of the overall benefits of doing both.
The feedback system is great, when it's all working as it should. When it's not working right, it's a royal pain and makes the conversion well worth the effort.
I hate to postpone this thing for yet ANOTHER day, but it looks like I'm going to have to postpone the pictures and the rest of the write up until tomorrow, monday at the latest. Had my step sister's wedding shower today, and going to dalonegha for the day tomorrow. So, I guess we'll see what happens.
So, I went down to Summit Racing today to pick up a job application, and wound up buying a roll of blue wire covers. As I was installing the covers, I remembered that I still hadn't finished this write-up. So, I figured since I didn't have anything else to do today, I figured I might as well. So. Here it is.
After you finish up the conversion, there should still be a bunch of wires coming out of this hole in the firewall. These wires lead to the truck's computer, which should be located here:
Now, you should be able to remove all of these wires AND the computer, but as a precaution, I followed each wire to find out where it went, and ensured that I no longer needed it.
You may also have a few vacuum lines left over, and you should be able to remove all of those too, plus the ports that are mounted on the driver's side of the valve cover. You should now have one vacuum line going from the distributor to the carb, plus the other assorted lines for brakes, etc.
After completing the clean-up, your engine bay should look something like this:
Parts that I removed:
From left to right: Truck Computer, TFI Distributor and Plug Wires, Vacuum Ports/Wire Plugs from the valve cover, Vacuum lines, At least 100' of wire (Some of the wires were leftover from the Holley Pro-Jection system)
ill be referring to this in a little bit as soon as i figure out my oil and coolant mixing problem may be doing a hole rebuild wont know till she is opened up. but this will be something i will be doing for sure.
Wyowanderer, thanks for sharing about that plug. I'll definitely be grabbing one of those.
diesellou86, It sounds like you might have a lot of work ahead of you. Best of luck, man. I'll tell you one thing, running this DSII system sure as hell gives a lot better gas mileage and power than the TFI/Standard carb set-up. I haven't done the math yet, but just to put it into perspective, before the conversion it usually cost me $40 in gas to make a round trip from my house to Douglasville, GA and back. About a 50 mile trip. Last week, I made the trip and only paid $25 for the round trip. So this system really makes a difference.
Is the egr valve used with this system? I have an '86 that part of the emissions stuff is missing. It has a new carb not sure what model but it is not the feedback carb. We don't have to pass emissions where I live. For now.
Does the wiring harnes have to be from a truck with a 300-6 or will any harness work. I know where a '78 is that still has the harness.
Thanks for the write up. This is what I've been wanting to do, but wasn't sure if it could be done.
Yes, the EGR valve stays where it's at. And you can mix and match carbs with this system, in fact quite a few people run this ignition system with a 4bbl, like an Edelbrock 1403, or a Holley 390 when they upgrade to a 4bbl intake manifold. I only used the standard YF carb as an example because it was easiest, it's standard equipment, and it's what I already had on my truck.
The wiring harness doesn't HAVE to be from a truck from a 300 I6, but it's recommended, especially if you plan on installing a factory tachometer. As far as the year model goes, I'm not 100% on that, but I would try to find one from an '80-'83, just to be on the safe side.
Really though, once you get all the parts, it's an astoundingly easy swap. Shouldn't take you more than about an hour to get it all in, plugged up and ready to go.