i have a 90 f-250 with the 351w and the motor is bad. i just bought a used complete 302 to put in it. the guy also gave me the ECU for the 302 engine. i should just be able to plug the 302 ecu in after the motor is installed and will work correct? also, does it matter 2wd or 4wd when it comes to the ECU?

 

Yep.....the ECU from the 5.0 will work just like it did in the other truck I'm sure.....but...I don't know if there is a difference between a 2x4 and 4x4 one. I don't think there is.....but......I been wrong before....lol
Someone will know for sure.
Good Luck

 

What year is the 302 from?
Did thy have the same transmissions?
You will also need the PS switch for the 302 or you will get an error code.

 

the 302 was from a 88 or 89 f-150. I know it was an automatic trans and so is mine.

 

You should be OK except for the PS switch.
If the 90 has an E4OD you will have big problems but if both trucks had AOD transmissions in them then you would be OK.

 

what is the PS switch? (power steering switch?) where is it located on the truck?

 

On trucks of that era with a 5.0 have the power steering pressure switch down by the steering sector.
Trucks with the 5.8 did not have one although the plug for one is usually hanging there. But if the ECU is out of a truck with a 5.0 it will expect to see one during the steering test. This lets the ECU up the idle when you turn the steering wheel.
Here is a photo:
http://i54.photobucket.com/albums/g9...hotos/PSPS.jpg

 

is the power steering pressure switch actually located on the ps pump or is it on something else?

 

If your 1990 F-250 has the E4OD you will not be able to swap computers. You will have to find the right computer for that combination - 302/E4OD. The problem is that combination was never available from the factory as far as I know, so you won't find a computer for it.

If the F-250 has a C6 then you're fine - but don't ignore this important detail.

 

With this vintage truck.. the 351 computer should have no problem whatsoever running the 302. Power production was very similar except that the 302 was particularly gutless until reved up.

 

i dont know what trans is in my truck now. it is a 1990 f250 xlt lariat 4x4 with a 351w. does anyone know what tranny came in that truck? can i use the ecu that is already in my truck with the 302 i am putting in?

 

Yes you can.

 

it doesnt matter that i am going from a 351 to a 302? i always thought you had to have an ecu for your exact combo

 

It should work OK but it may run a little rich until it warms up and the O2 sensors take over.

 

My Jimmy with a 305 tbi has the ecu from the original 4.3......Throttle body also......works fine.