Hi I'm doing an engine swap from a 5.0 efi to a 351w carb'd. I'm pretty deep into it, but i've noticed a few bumps along the way. I am in need of a wiring diagram. also any insight on things others have run into would be great!

I know i needed a different distributor, flex plate, torque converter ignition system ect... what i didn't notice is the wiring is different, not going to be plug and play . So anyone done this before that can offer insight?

Thanks,

Randy

 

Wow, that's a helluva jump backwards especially for the electrical system. There is a ton of sensor wiring and EFI equipment wiring that you simply don't need. However, sifting through the complexities of the EEC-IV wiring harness to pick out the few wires that could be used is a tall task that I wouldn't even consider undertaking. You would be better off pulling the harness and putting the required wiring in after the swap is complete.

Out of sheer curiosity, why go backwards to a carburetor from the far more reliable and more easily troubleshot EEC-IV engine management/fuel injection system? These days EFI equipment is easier to come by than carburated equipment.

 

Honestly, the reason why is the engine came with an edel brock setup; carb, intake & fuel lines, the previous motor was blown.

I'm looking at either getting a painless or making a harness.

 

Find one in a junkyard with the 351 and transfer all the wiring,when I changed the engine harness in a 84 crown vic I could see it was also made for the carbed 351 motor. If the trucks were made the same all you would have to do is remove the EFI harness and plug in the carb harness.

 

I've been looking but it's hard to find them...normally, they are gone, clipped in half, or EFI...i guess i'm going to keep looking.

 

You can use a harness from a carbed 300,302 or 460,I used a 300 harness to get rid of the VV carb and crank trigger ignition on a 351 that was in my 82 F250. 87 was the last year for a carbed 351 and 460.

 

I have an '83 but it has the 351W. My EEC harness is shot and I'm trying to find one now too. I have a carb'd 351W but even changing from the stock engine to the Edlebrock monster that I'm evoling too is presenting challenges. I'm completely removing the emissions EGR and things that aren't absolutley necessary. I'm trying to remove my computer (EEC) all together to make it a more "independent" system. I would assume that you'd need to change your EEC from the FI model to an older model EEC like mine, if you're planning to run a carb. Probably too many changes between the engines to just try and adapt to...without changing the EEC too.

 

On the 82 I changed from the crank triger ignition and VV carb the computer harness was sperate and plugged into the main harness,I removed it and plugged in the carb harness and all was fine. Dont know how the EFI harness was on those but probably close to the 82.

 

So to be clear on my end...you had an 82 and removed the carb, and installed an EFI using the same EEC harness (separate form the accessory harness) and all was fine, even though you now employeed the EFI instead of carb? Sorry, RandyS503...I'm trying to learn too.

 

I removed the computer controlled VV carb and crank trigger ignition and installed a non computer controlled 2 bbl and duraspark ignition. If the 86 is like the 82 you should be able to remove the EFI harness and plug in a carb harness since the 351 and 300 had a carb and not EFI so I doubt Ford made a different main wiring harness untill all motors went EFI in 88.

 

Man, thanks for the input! So basically, I should be able to do away with the EEC and that harness? (I know that you feel that you answered that pretty clearly before...but I am new at this and just want to make sure.) I've always felt that since it's a carb'd engine with timing and a distributor, that I should be able to get ride of the emissions and just run it "simple". But I know that I couldn't do it with the EEC and it's harness b/c some of it's inputs would have to be "tricked" in order for it to it run right.

Us newbies...what can you do? Of course you could let us go and screw things up for ourselves..but that wouldn't help anyone and it would probably ruin some really fine vehicles. Thanks for the help!

 

I am going to be hitting the junkyards next weekend looking for front suspension parts for my 2wd bronco swap and will see if I can find a harness for you.

 

I got a 88 diagram......

 

RandyS503, when I started on my '83 I went and bought a Haynes book (book #36058) from Autozone and it has wiring schematics from 1980 thru 1996. I also found the Chilton book (book #26662) at O'Reilly Autoparts and it has wiring schematics from 1976 to 1986. You may want to think about picking one of those up. you can also run some searches on the net and you may get lucky enough to find one that someone has scanned. Like I said before, my '83 has a 351W with carb, so you can alsways check that schematic for comparison.