B2 4.0 Swap

[lowsinthe20s]

Hello, New to the forum.

Currently doing a B2 4.0 Swap. Seems like a lot of good info here. Hope to learn a lot. I think my biggest concern is the wiring. I'm getting a M5OD-R1 Trans to matte to the 4.0. I have checked out some of the tech articles, but any advice or suggestions would be appreciated.

B2 is an 89, 2.9L, Manual, 2wd.

Donor is a 94 Explorer, 4.0L Auto, 4wd Manual.

I'm also swapping the 4wd to the B2 as well.

 

[lil_Blue_Ford]

Assuming the Explorer donor puts the computer in the same position as the Bronco II, all of your wiring should be on the drivers side. The plugs will be different and since you’re going manual there’s going to be some excess wire in the harness, stuff that would connect to the auto transmission. You may or may not have to rig up for the neutral safety switch and backup lights, it’s been awhile since I messed with it. I found the Explorer harness to be more different than a Ranger harness in comparison to the Bronco II harness. Since I had both options and the Ranger harness was from a manual, that’s what I went with.

The computer from the auto will run things as a manual, but not very well, you will have a persistent high idle and it will always complain that it doesn’t “see” the auto transmission.

The fuel system is not plug-n-play, you will have to do some adapting. I built some janky adapters when I did mine. It’s worked fine for many years, but I think when I get back to that project, I’m just going to make some new -6 AN lines and fittings and do it right. That’s probably the most expensive way to resolve it, but I ended up getting into -AN stuff for another project and I like the utility of it, so that’s the way I’m doing things these days. There are other ways to overcome the problem.

Use the 4.0 flywheel/clutch/slave. Get it for a 94 Ranger 4.0 and that should work. It’s heavier duty than the 2.9 one.

 

[lowsinthe20s]

I was planning on getting an manual ECU to avoid an codes. Guess I might look for a manual harness as well.

How much of the fuel system ? Just the lines? Will the B2 fuel pump work or should I use the Explorer?

My plan was to get a 4.0 flywheel and clutch. So the slave is different on the 4.0 as well?

 

[RonD]

Welcome to TRS

Good page to Bookmark here: https://www.therangerstation.com/tech/

Look in Engines section for 4.0l swap info

We have a sister site here: https://www.broncocorral.com/

And they also have a Tech section as well, seen here: https://www.broncocorral.com/tech_library/
Another good page to Bookmark
They have a few different 4.0l swap articles


Any 4.0l engine wiring harness up thru 1994 will have the wires for clutch switch and automatic, just the computer software was different, and automatic had an added harness which can be unplugged
The wiring at the computer was the same

 

[lil_Blue_Ford]

I was planning on getting an manual ECU to avoid an codes. Guess I might look for a manual harness as well.

How much of the fuel system ? Just the lines? Will the B2 fuel pump work or should I use the Explorer?

My plan was to get a 4.0 flywheel and clutch. So the slave is different on the 4.0 as well?

Yeah, ideally a manual ECU. If you can get the manual harness even better, but the auto harness can be made to work, if needed.

Just the lines for the fuel system. Technically it’s actually just the ends up by the fuel rail. If I get a chance tomorrow I’ll go down to my choptop and grab a picture of what I’m talking about and what I did.

I’m not sure offhand if the slave is different, but I’d replace the slave with the clutch anyway. It’s usually recommended.

 

[lowsinthe20s]

Yeah, ideally a manual ECU. If you can get the manual harness even better, but the auto harness can be made to work, if needed.

Just the lines for the fuel system. Technically it’s actually just the ends up by the fuel rail. If I get a chance tomorrow I’ll go down to my choptop and grab a picture of what I’m talking about and what I did.

I’m not sure offhand if the slave is different, but I’d replace the slave with the clutch anyway. It’s usually recommended.

Awesome! My biggest challenge is going to be the wiring. Is there any documentation out there on what wires are used and what is not? Is there any PIN swapping? I also plan to keep the B2 dash will that be an issue for the tach to work?

I have been able to find a manual ECU. If the manual harness is the same just missing some wires it would be great to know which ones those are.

 

[lowsinthe20s]

Welcome to TRS

Good page to Bookmark here: https://www.therangerstation.com/tech/

Look in Engines section for 4.0l swap info

We have a sister site here: https://www.broncocorral.com/

And they also have a Tech section as well, seen here: https://www.broncocorral.com/tech_library/
Another good page to Bookmark
They have a few different 4.0l swap articles


Any 4.0l engine wiring harness up thru 1994 will have the wires for clutch switch and automatic, just the computer software was different, and automatic had an added harness which can be unplugged
The wiring at the computer was the same

Thank you for the info. I have been to a few of these sites poking around. Do you have any info on which harness is the automatic one? I have removed the engine harness and nothing on it was plugged into the trans. I assume I need to remove the fuse block and remaining engine bay wiring for the swap.

 

[RonD]

Manual or automatic computer engine wiring harness's are the same, up thru about 2000
Computer software was different
i.e. all Rangers were built/wired as manuals, if an automatic was installed then a different computer was used and an added auto harness was plugged into the existing wires of the manual harness

Think of it as an Option, same wiring harness was used on all XLTs, so the base wiring for power door locks and windows would be there but the rest of the harness was not added if it was an XLT with no power group option


All computer harnesses had the wires for automatic solenoid hookup at the computer end, just added harness wasn't plugged in at the transmission end
And the manual trans computer didn't have the software to "look for" or operate the solenoids, so didn't turn on CEL if they were "seen"

Engine wiring harness's that can be different are with or without EGR and Cam sensor, and of course MAF or MAP
But no difference between manual or automatic harness's at computer end

 

[lil_Blue_Ford]

@lowsinthe20s

Here’s my janky adapter setup for the 2.9 to 4.0 fuel system

 

[lowsinthe20s]

@lowsinthe20s

Here’s my janky adapter setup for the 2.9 to 4.0 fuel system

View attachment 90439

WOW!! Some AN fittings would be a nice upgrade

 

[alwaysFlOoReD]

I once bought an 84 b2 that had already been 4.0 swapped. They filed the gas tank opening to fit a mustang high pressure pump from what I remember when I talked to the original builder several years after I bought it. I would look at swapping a high pressure pump into the tank...

 

[lil_Blue_Ford]

WOW!! Some AN fittings would be a nice upgrade

Yeah, funny thing though, that’s held up better than motors in mine. Gone through three or four 4.0 motors and probably 10-ish years. It works, but it’s definitely janky. I did that long before I got into -AN stuff and that was one of the things on my mind when I started buying AN, that when I next drop a motor in, clean that up nice.

 

[lil_Blue_Ford]

I once bought an 84 b2 that had already been 4.0 swapped. They filed the gas tank opening to fit a mustang high pressure pump from what I remember when I talked to the original builder several years after I bought it. I would look at swapping a high pressure pump into the tank...

His is an 89, so it already has the in-tank high pressure pump

 

[SenorNoob]

In my case (91 harness) the auto/manual part of the harness had a connector on the firewall that could be unplugged running to the transmission. It was about a 2.5 foot sub-harness that ran to the transmission. Plug and play.

Looking at the parts I have left, it may have had the O2 connector as well.

You want all the wiring from under the hood of the 4.0 vehicle except for what runs to the headlights. Might be easier to take that too. I don't remember. I put my harness on a diet. More came out than went back in.

If you can, get the under dash side of the big white plug. And several inches of wire! Then you can cut the "salt and pepper" connectors off the 2.9 engine harness (Don't forget to leave some wire!) and build an adaptor. That way all of the things that need to spliced will fit on your desk/kitchen table.

 

[lowsinthe20s]

Will any 91-94 manual ECU work? or does is have to be a 94 since my donor is a 94?

If I have a Manual 4x4 does the ECU matter?

Also is this the correct/best trans for the 4.0. I found one online. Doesn't say Ford but I think Mazda used the Ford Trans or vis versa.

91-94 Mazda Navajo 4.0L 4WD 5spd Rebuilt Transmission "M5R1 M50D"

Thanks.