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I have 1984 f150 300 inline 6 with the feedback carb and what i believe from research to be a duraspark 3 ignition. The kicker is that i bought the truck and drove it home with no computer, no vacuum lines, and 90% of the wires cut. Everyone who has seen it can't believe that it runs at all much less for months but now it's acting. Rather than replacing the hack job by the
previous owner I've heard that going to duraspark II and a duraspark II era carb would be much easier and reliable. I've seen lots of write ups on wiring harness for a duraspark 2 swap but what about the carb or intake? Do I need to swap that also? I plan on finding donor trucks at junkyards for the swap. Anybody done this before that has pictures or a link to a good write up would be greatly appreciated.
Lots of people have done it, but I don't know if we have a step by step write up. I have never heard of people having to swap the intake.
I recommend you do it in stages. Do the dist swap and ignition first and get it running, and then do the carb. It will run alright with the feedback carb(if it's any good) till you can get another one without all the wires.
As always, Dave is right. Do it in stages, with the electrical part first. The DS-II swap may make it run so well you don't have to replace the carb as the amount of control the computer had on it was minimal. However, if you do decide to change it out I recommend going with the carb that 1986F150six used. He has a thread on here about his carb and the MPG he's getting, so do a search for it. I'm thinking it is one off a 1970 300 six, but anyway his thread has all the info.
I just finished a gm hei ignition swap on my 86 300. It was really very very easy. Im not trying to sway you from a ds2 swap. But i could help you out with how to do that one if you went that way. Im still using my feedback carb for now. Truck runs much better with the gm module and 80 model distributor.
Most [non-California] trucks, 1984-1986, had the feed-back system. The computer controls the carburetor and distributor timing. When working correctly, this system performed quite well. However, when all sensors, wiring or vacuum lines are not functioning as designed, the performance suffers.
When I purchased my 1986 with 4.9L engine, the performance was poor and gas mileage was horrible. I switched to the Duraspark system [modified with MSD ignition module] and have enjoyed much better overall performance and efficiency.
We will try to help you as you undertake this adventure!