Are the computers and Wiring Harness the same in a 302 v8 and 300 I6. I recently bought a '93 F-150 xlt 302 4x4 5 speed for $500. The truck is in great shape just had a bad motor. I bought my co-workers truck for parts, same exact truck just a '94 and it's automatic for $450. Truck ran and drove great, just a rotted out POS. I finally got the good 302 in my truck and enough hooked up to try to start it up before I put it 100% back together. The engine will start and run like crap. THE CATCH is both trucks didn't have the original motors. I do not believe it is a firing issue, I tried both of the firing orders, it does the same for both. My truck according to the title originally had a 4.9 inline, the parts truck just had a newer crate motor. I now believe the man I bought my truck from, or the guy that sold it to him, everything they did to the truck, all of the money they put into it, they never changed the computer and wiring harness. So if my truck has a 6 cylinder wiring harness and/or computer then cylinder 7 and 8 are not working theoretically

 

In short no, they are different, the 93 will be batchfire speed density, the 94 did it have a mass air set up?
Yes you need to match harness and computers, especially if you swap harness from 92+ yes they may bolt together(engine harness) but I have not seen one pinned the same.
What engine trans combo do you have? more info, if you have 5.0/e4od, 5speed?

Curtis

 

An I6 harness will not connect to a V8, for starters there would only be 6 injector plugs and all the components are physically located in different places on the motor so you would know that something was wrong when you were hooking it all up.

By chance did you move the part of the wiring harness connected to the motor over when you swapped motors? If so that's a big no-no.. there is no guarantee at all that these two wiring harnesses are pinned the same at the block connectors, so you would need to remove the upper intake and put the original engine harness back on. And the computer that came with the automatic donor truck is not compatible with your 5-speed truck so don't put it in.

 

I have the 5.0 with a 5speed tranny, last fall before winter is when i pulled the motor out of the donor truck, I didn't take the computer or the wire harness and fuse box that plugs into the computer, I only kept the part of the wire harness that is connected to the engine. I sold the truck to this guy who wanted the truck for the bed and automatic tranny. Funny story actually, the guy who bought the truck off of me, the deal was 400, he originally paid 250 dollars, I hand written two receipts stating that he still owed me 150 dollars and that he will get the title when he pays up the rest. He tried screwing me saying that the transmission was garbage because the oil pan was a little rusty and he couldn't disconnect the tranny from the cross member. I didn't feel like dealing with the b.s. so I gave up on the whole ordeal. Recently about a month ago, I am calling a man who has an ad in craigslist about a ladder rack for 100 dollars and when I get to the location its the same guy who bought the donor truck from me and it is still sitting where he last parked it after removing the bed. He was never able to scrap it with out the title. I tried to make a deal with him on trading the ladder rack + 50 for the title and he wouldn't go for it. Then he realized how stupid he is for not going for the deal. I just got off of the phone with him, I'm going there 2morro morning to give him the title and get the wiring harness that I should have taken in the first place and im going to try to get the rims also cuz he is only going to scrap the truck and have to pay 5 dollars a tire anyways.

 

That's your problem, you need to take the upper intake off the motor and install the original wiring harness that came with your truck.