4.0 swap

[litlred]

ok, ive been doing alot of reading on this subject but im still uncertain... im swapping a 4.0 from a '91 explorer with bad automatic trans to a '90 bronco ii with good 5 speed.. im not sure which computer to use, i know the auto is computer controled so i should use a manual computer but will the 2.9 computer work for the 4.0? thanks for any help

 

[short bus]

you need the 4.0 comp for the motor

 

[Clem]

Does he need the computer for the 91 automatic or a standard?

Ray

 

[SpotNStalk]

Does he need the computer for the 91 automatic or a standard?

Ray

I did the same swap except my BII is an '89. I picked up a computer from a '91 Explorer with manual transmission. I could get the rig to start and idle with the 4.0 computer from the donor vehicle which was an automatic but it bogged and died when you hit the gas.

 

[litlred]

Ok, so I need the 4.0 computer. So I'm running a manual, so I need to pick up a 4.0 manual computer. What do you think that will cost from the junk yard? Which wiring harness did you use? Thanks.

 

[BlackBII]

Did you read up on this in the tech library and read the stickies?

You will need the entire engine bay harness from the 4.0, it starts at a big plug on the firewall on the drivers side and goes all the way over into the power distribution and then down through the firewall on the passenger side to the computer.

You'll need a computer from a 4.0 manual truck. I bet the junkyard wont charge you more than 25-50$ for a computer.

The tranny in your BII might be a FM146, and in which case will not be happy behind a 4.0, but i've had them work just fine. Idealy, you'll want an M5OD.

You'll also need the clutch, flywheel and starter from a manual 4.0.

Don't forget the radiator.

 

[litlred]

Ok ill reword my question. Should I use the harness that I have now from a 4.0 with automatic, or should I try to get one from the junk yard that matches the computer (4.0 and manual) that ill be getting? I'm sure its different where the transp plugs in. Thanks

 

[BlackBII]

Use the Auto harness you have. But go get a manual computer.

The tranny harness is different, but you can get the tranny harness from a manual and plug it into your main harness. Not that it really matters tho...

 

[CopyKat]

The Manual 4.0L will run fine with an Auto ECU. It will just switch the timing around as it thinks it's shifting at specific RPM's. Nothing other than possibly the converter lockup is ECU controlled on the A4LD.

 

[kunar]

and if you expect this to be a plug and play swap, you need a harness from a 2nd gen ranger with a 4.0, the explorer wiring is totally different. check into fuel injectors too. you may end up needing them from the donor you get your harness from, i dont remember for sure.

 

[litlred]

Thanks for the help, ill check it out.

 

[arineod]

and if you expect this to be a plug and play swap, you need a harness from a 2nd gen ranger with a 4.0, the explorer wiring is totally different. check into fuel injectors too. you may end up needing them from the donor you get your harness from, i dont remember for sure.

what if you grab the dash and everything out of the explorer, wouldn't that work?

 

[SpotNStalk]

what if you grab the dash and everything out of the explorer, wouldn't that work?

Not trying to be argumentative with CopyKat but my '89 with the automatic ECU from a '91 explorer didn't run right at all. I put an ECU from a manual '91 explorer in and it ran great.

You can use the wire harness from the automatic but will need to make a jumper for the neutral saftey switch wires in order to get it to fire up.

I don't know about the swap into a '90 but my '89 was plug and play in order to get the engine to fire but I had no lights to the rear of the vehicle and had to have someone smarter than me fix it.

 

[SpotNStalk]

Ok, so I need the 4.0 computer. So I'm running a manual, so I need to pick up a 4.0 manual computer. What do you think that will cost from the junk yard? Which wiring harness did you use? Thanks.

I can get them for about $20-25 from the pull a part where I am at. I swapped in the dash and wiring harnesses from the explorer because the stereo had been ripped out of my bronco resulting in broken mounts, etc. and they were the same color and everything.

 

[CopyKat]

Not trying to be argumentative with CopyKat but my '89 with the automatic ECU from a '91 explorer didn't run right at all. I put an ECU from a manual '91 explorer in and it ran great.

Whatever. Buddy of mine was running a 91 Explorer Auto ECU on his Ranger that we swapped to a 4.0L 5 speed. He ran it for a week like that. Sure it throws a Check engine light but it still ran. We have since gotten a proper manual ECU for it.

Like I said it will run fine, I didn't say it would run like a raped ape!

I've got superchip chip from a 93 Explorer Auto. I've run it on my 91, 5 speed ECU and it runs Good. I can feel where the timing changes for shifts, and it throws a CEL. But again it still runs.