‘88 2.9 to 4.0 swap

[C_meista22]

Hello all I’m new here to the station, I blew my 2.9 and I’m looking to do a 4.0 swap anyone have instructions to do so. I heard the wiring harness needs some changing around but I’m not sure. Any instructions or tips would be greatly appreciated thank you!

 

[BlackBII]

Lots of tech articles and threads around here on this subject that go into detail on the swap. The gist of it is for an '88, you'll be doing quite a bit of wiring work and you'll need the 4.0 and accessories, engine and ECU harnesses, flywheel, clutch, starter, transmission, some fuel lines and other stuff, but it's mostly a bolt in swap.

 

[DPDISXR4Ti]

The ideal way is indeed to do the full wiring swap from the 4.0 donor. That said, if you want to do more of a "cut & splice" approach, you could take the approach I did when converting to EDIS-6 on my 2.9. Details here... https://forum.merkurclub.net/forum/viewtopic.php?t=42772

 

[C_meista22]

If I get a 4.0 ecu harness is it a pretty simple plug and play?

 

[BlackBII]

If I get a 4.0 ecu harness is it a pretty simple plug and play?

On an '88, no. The dash harness and firewall connections are quite different from the 89+(4.0 was introduced in '90)

If you swapped the dash and it's harness along with the engine bay, engine and ECU harnesses from a 4.0 Ranger/Explorer, it would be mostly plug and play, with some attention needed on the tail light wiring, fuel pump wiring, rear abs wiring, etc

 

[DPDISXR4Ti]

On an '88, no. The dash harness and firewall connections are quite different from the 89+(4.0 was introduced in '90)

^^^ This is precisely the reason I suggested my alternative approach. Even with my approach you need to do some thinking and have a good understanding of what you're doing. But I would contend it is easier. Keep in mind, even though my conversion was done to a 2.9, at this point, I could drop a 4.0 in and electrically need to change nothing.

 

[C_meista22]

not to be mistaken I thought the 88 year dash didn’t need to be swapped due to the tachometer being added that year. This is coming from my uncle who worked for ford in the 80s

 

[C_meista22]

Mine was built in August of ‘88 so I think ford had started making the Ranger with ‘89 features I could be horribly wrong though

 

[SenorNoob]

There are a few ways to do this. Easiest is to buy a newer truck. Second easiest is to swap the dash I'm told. Then the wiring just plugs in. Third is to effectively make the 4.0 engine harness standalone. That's the route I took. I wanted to maintain the earlier dash for appearance.

88 and 89 are very different. Are you sure you have an 88? Post a picture from the front and of your dash if you aren't.

 

[C_meista22]

There are a few ways to do this. Easiest is to buy a newer truck. Second easiest is to swap the dash I'm told. Then the wiring just plugs in. Third is to effectively make the 4.0 engine harness standalone. That's the route I took. I wanted to maintain the earlier dash for appearance.

88 and 89 are very different. Are you sure you have an 88? Post a picture from the front and of your dash if you aren't.

Yeah I’m 100% sure I got an 88 lol.

 

[C_meista22]

I’m only asking because I know ford likes to do mid year changes to their body styles sometimes. I got the 88 grill and interior

 

[C_meista22]

On an '88, no. The dash harness and firewall connections are quite different from the 89+(4.0 was introduced in '90)

If you swapped the dash and it's harness along with the engine bay, engine and ECU harnesses from a 4.0 Ranger/Explorer, it would be mostly plug and play, with some attention needed on the tail light wiring, fuel pump wiring, rear abs wiring, etc

 

[SenorNoob]

I only asked cause you said August of 88. That would typically be an 89 model by todays standards.

I ran a supposedly rebuilt FM146 behind my 4.0 for roughly 8 years using the 2.9 flywheel and clutch. By the time I took it out it was real easy to get 2nd instead of 4th. Not sure why.

Tach has nothing to do with dash/engine wiring beyond the signal having to come from/to. The 88 dash harness uses two small round connectors (like the Mustang "Salt and Pepper" connectors). 89+ uses a single large round connector (the Big White Plug).

I found in my case all of the wire colors were the same right there. The only thing that gave me trouble was the neutral/clutch switch wiring. I had 3 wires at one point.

 

[C_meista22]

I only asked cause you said August of 88. That would typically be an 89 model by todays standards.

I ran a supposedly rebuilt FM146 behind my 4.0 for roughly 8 years using the 2.9 flywheel and clutch. By the time I took it out it was real easy to get 2nd instead of 4th. Not sure why.

Tach has nothing to do with dash/engine wiring beyond the signal having to come from/to. The 88 dash harness uses two small round connectors (like the Mustang "Salt and Pepper" connectors). 89+ uses a single large round connector (the Big White Plug).

You think they used the big white plug on mine from August of 88 or is that a long shot? And you used a fm146 on a 4.0 with no issues?

 

[SenorNoob]

I've never seen a BWP on an 88. Not saying Ford didn't build a few. They did lots of things that way.

I did. With the 2.9 clutch. It slipped before I was able to break the transmission. I tried shortly after installing it to do a burnout and just ended up smoking the clutch badly.