Using 97 4.0 in 2000 3.0, need help

[Loboy154]

Planning to Switch both engine and tranny, have both trucks, big question is how to deal with fuel supply. 97 has return from fuel rail and 2000 Dual Fuel has single line to fuel rail. What is the best way to deal with this. Your help is greatly appreciated.

 

[RonD]

Well you will need to swap computer and wiring harness so I guess swapping fuel system would be best.
Drops tanks and swap them.

Not sure if buying a used '98-'00 4.0l fuel rail with injectors will work with the '97 wiring harness or computer, or if the '97 computer could accurately control 65psi injectors vs 35psi injectors, as far as fuel metering.

Working Flex Fuel sensor is worth $650 new from Ford, maybe $200 used, 65psi fuel pump is worth something as well

 

[Loboy154]

which part of harness,where is the computer located?

 

[Loboy154]

Update on Swap- need help

Got the 4.0 in, had to do some mix and match and fab on motor brackets to fit up to 3.0 mounts.

Used the 4.0 harness from the 97, used the fuel pump and lines from 97 in the 2000 tank.

I am getting fuel to the rail can hear the pump run, but no start. I even sprayed starting fluid in intake, no effect. I tried the 2000 pcm and it will not start, same with 97 pcm- I get the theft light flash with the 97.

So what do you recommend

 

[cp2295]

Honestly if i was you i would've used a 98-00 4.0 computer and fuel rail. The rail is returnless and the computer is in the same gen which makes life a lot easier. i did this swap and i had a 99 3.0 and put in a 98 4.0 and it was a massive headache, i ended up having to rewire the 3.0 harness and use the 98 4.0 computer to get it to run. No codes or anything so far. And the best pcm to use is the 98 4.0 because you won't have to deal with PATS at least i didn't. The light flashes everytime i start it but it starts regardless.