HI, Im new here, so forgive me if this is in the wrong section.
i have a 92 flareside 4x4,originaly with a 300 six and a light duty (mazda?)5 speed. i installed a 351 from a 97 f250 and the zf 5speed. i have the wiring harness for the 97, but not the computer. how do i make it run?
i tried a 97 computer, it wouldnt plug into either harness. i tried a 92 351 computer, it would run if you put gas in the intake, but wouldnt run on its own.there is fuel pressure at the rail, so im thinking that computer had the right ignition, but wouldnt operate the injectors properly.i can only find 2 computers for a 351/5speed combo, and the one didnt work.
to complicate things more, 97 was the year the 150 changed, but the 250 didnt until the next year, so some parts stores dont believe a 97 351 even exists.
so, the question is, do i use the 92 harness or the 97, and which computer do i use?thanks.

 

ok, i'm trying a 96 351 computer.i was going to use the 97 harness, but there are diferances where it goes to the cab. according to my haynes manual, 92 6cyl and the 96 351 (over8500 gvw) use the same wiring diagram, even all the pins on the computer are the same. however, the connection between my engine harness and my stock harness have some pins in differant positions. i tore apart the engine- side harness connector on my 6cyl to see how hard it wound be to switch pins around. it doesnt look to difficult, so im gonna give it a whirl. anyone have any experience doing this? am i asking for trouble, or will this work if i follow the wiring diagrams carefully? or, is it possible for a dealer to flash a computer to work with my combination?

 

I think you may be running into an OBD-2 vs. EEC issue here. Your TRUCK is EEC. The 97 is OBD-2 and I'm pretty sure the 96 over 8500 GVW is EEC.

 

thanks for the reply, i forgot about the obd 2 thing. as far as i can tell, the 97 f250 over 8500 351 is the same as the 96, or else mine was a 96 leftover titled as a 97. i know the f150 (and lt duty250?) had the new bodystyle, and the 4.6/5.4, not the 351. ive realized no matter which computer i use, if my engine harness pins arent in the same place as the harness it plugs into, it wont run. i probably had the correct ecm and returned it, not knowing the true problem. anyone know where i can get a diagram of the harness plugs?

 

You may be right - the over 8500 97 may still be EEC.