I am currently working on swapping a motor in a 1990 f250 and I bought a donor truck which is a 94 f250. I just finally got the motor pulled from the 1990 today. And now im stuck with a problem. The motor from the 94 donor truck has a distribution box, and the 90' doesnt. So can i just swap the motors wiring harness from the 1990 motor to the 94 motor?

 

Keep everything from the original 1990 motor/harness. Discard the engine harness from the 1994 donor. Sometime around 1993/94 Ford moved the location of the Air Charge Temperature (ACT) sensor from the intake manifold to the airbox. You may have to swap the intake manifolds to retain the original location.

 

Right.. you can't use any wiring from the '94 so don't even try, if the '94 motor has the IAT sensor in the airbox then you will have to either swap the intakes or drill and tap the '94 lower for the sensor. The other thing you will have to deal with is the distrubutor, Ford moved the ignition module off it to the fender as well but you can't just swap distributors because the '90 motor has a cast iron flat tappet cam and the '94 has a steel roller. You want to use the '90 distributor but first you need to put the steel drive gear from the '94 distributor on it, then it'll drop right in and plug into the '90 harness.

 

Just to verify, 94 5.8L ACT is located in the lower manifold.

 

Ok thanks guys, I was thinking of just relocating the Ignition module to the 90's fender, is that possible?

 

Do you know if I can just re-locate the Ignition module into the 90's fender?

 

Yes you could but you'll have wiring changes to make as the two systems are slightly different and the whole idea with this type swap is to avoid wiring changes if at all possible.

 

Ok so the things i need to do is, look for the IAT sensor, and swap the Distributors? Any thing else? and thank you for your help.

 

That should be it.