1990 2.9 ranger 97ohv 4.0 swap

[Tymoto99]

Just looking for a small bit of help with my project..

I have the 97 harness out of a explorer the engine and the m50dr1 from my 2.9 ready to go in...

my main question is how can I get this 97 harness to work stand alone and if not what older harnesses can I use with this engine? or am I limited to it only plugging into a 97 harness.

 

[19Walt93]

1990 ran EEC IV and 97 was EEC V/OBD II, it isn't going to be plug and play. @adsm08 might know a lot more about it.

 

[PetroleumJunkie412]

Better off with a new cam, lifters, and a standalone pcm.

Tunes are free, and in the 2.9 section.

What you're describing is going to be a headache, and overall probably not worth it.

2.9 will produce respectable power with much, much better fuel economy.

 

[RonD]

For the 1997 you also need the MAF sensor and the 4 O2 sensors to make it work, I think Explorers use dual exhaust, so would be great to get exhaust system with the engine, it will have O2 bungs, and sensors

It would be good to get an EVTM for 1997 Explorer, it tells you which wires go where, so you can interface it with 1990 engine bay wires, mostly for 12v and ground hook ups

The engine/computer wiring is "stand alone" for the most part, if explorer was an automatic then it will work, but CEL will stay on all the time because no transmission solenoids connected or working
But you can have the computer reprogrammed to delete automatic software

If this is a 4.0l OHV engine and NOT a 4.0l SOHC engine, then you could use a 1997 Ranger manual trans computer instead

 

[adsm08]

Making a 97 Explorer system be stand-alone is easy, or hard, enough, depending on how well-optioned the vehicle was. 97 was the last year that didn't have PATS, so that should simplify matters, but you will still have a great many issues to overcome, not the least of them being the fact that certain things in the harness will not be in the correct locations on your body. Also, your diagnostics wiring will be complicated by the fact that the wires for the DLC on a 90 exist only in the engine bay harness, and the wiring for the DLC in a 97 resides partially in the dash harness.

The easier solution is to get an EEC-IV computer and compatible wiring from a 90-92 Ranger or 91-94 Explorer. This will make the wiring portion of your swap nearly plug and play going into a 90.

Explorer harnesses of any year are less than optimal for swaps into a Ranger, but the 91-94 ones can be made to work easy enough. The issue is that on Rangers all the wiring for the rear lights, and the fuel pump originate in the dash harness, go through the big white cannon plug at the fire wall, then run along the frame in the rear section of the body harness. In an Explorer of any year those same wires originate in the dash harness, but split off and stay inside the body, running under the carpet to the rear of the vehicle. If using an early Explorer harness you need to swap the shell of that big connector from the Ranger harness onto the Explorer harness leaving the needed wires from the Ranger in the connector. You can't just swap them into the Explorer connector because the holes are closed. Or more accurately they were never drilled open, and trying to do it after the fact usually produces wires that don't stick through the shell straight enough to mate to the pin on the other side.

 

[Tymoto99]

Thanks for the input everyone still trying to decide what route to take!

 

[Rimjam]

I have two long time friends, one a repair shop owner the other an engineer. Both made the swap you're talking about, both say NEVER AGAIN!