96 4.0 into 88 2.9 Can I do this?

[milehibry]

Newbie to this site!
Awesome wealth of knowledge!
Thanks in advance for ANY info!
I have a rolled '96 Explorer 4.0/stick 4X4 I desire to use as the donor for my '88 Ranger 2.9/stick 4X4. I realize a TON of differences! Engine/wiring is really the biggie! REAL question is can I use an OBDII engine w/an earlier(90-94) Ex or Ranger wiring harness.
My thot is to NOT use the wiring harness from the '96 Ex...TOO many un-needed wires, etc. SO...can I use a pre '95 wiring harness(OBDI) to utilize my '96 4.0 motor? Are Crank/Cam sensors, etc the same...?
Sorry for the LONG question!!
THANKS!!

 

[2ranger87]

I'm not 100% sure of the exact years, but i'm pretty sure the best harness to retrofit would be out of an early 90's Ranger (90-92?) and the computer from that year.

You will also need to change over the harness/ sensors and injectors off your '96 with the earlier parts.

When you change to the earlier harness, you will not need a cam sensor. They did not start using them until '94 (there might be a handful of '93's that had them) and the egr will also not be used.

I'm sure someone with a little more "hands on" experience will chime in (AllanD)

 

[AllanD]

a 1991-92 Ranger is likelier easiest, but there are other issues at play here.

To use 1990-92 wiring will require swapping out the injectors
in addition to swapping out ALL the sensors and the upper intake.

But the good news is that the Y-pipe you have now will work on the 4.0, it bolts right up to the 4.0 manifolds.

AND it's single HEGO which will "play nice" with 1991-92 management.

I'd definatly look for a ranger harness because there's so much less irrelevant
stuff that gets in the way, what stuff? I'll class it all loosely as electrical doodads that you don't have don't want and can't install anyway (rear wiper?)

a 1991-92 Explorer harness can be made to work, but it involves a bit more brain sweat.

The First thing I'd go hunting on ebay for is a "EVTM" for a 1988 Ranger.

These are the "Electrical, Vacuum troubleshooting manual"
They are NOT a wiring diagram

Frankly I can read a wiring diagram perfectly well, but unless you worked in the electronics industry don't even try.

what they do is eaxplain circuit by circuit how things work
and there will be a bit of flipping back and forth to identify
things and determine wire colors they will tell you what you
need to know without all those tiny lines on a wiring diagram
putting you into brain lok.

After that I'd go looking for a 1990-92 Ranger harness
And whan I say harness I mean you start at the computer at the kick panel
and take everything (EVERYTHING!) that looks like wire under the hood
(yes the harness for the lights as well.)

Once you have your donor harness THEN you know what computer, sensors
and most importantly what EVTM you need to go with that harness
Nextstep is to remove the harness from your truck by the same method
start at the computer and shove the connector through the firewall
but here you get "sneaky" when you come to a wire that goes to a headlight, horn or marker lamp, washer reservoir? split the harness tape and peel it out as you go...

when you get to the cluster or connectors on the drivers inner fender cut them off about four inches from the connector on the HARNESS side (the harness you are removing)

you will need a GOOD crimper and a BUNCH (~75) red heat sealable
wire splices, the kind with the heat shrink sleeve that are filled with hot melt glue

You'll also need 25-30 of the "blue" and around a dozen of the "Yellow" splices

I tell people to buy 100 red, 50blue and 25yellow you WILL make mistakes.

a 1996 will have EGR, you don't want it.. EGR is not the problem
but the sensor that tells the computer that it is working correctly
is utter crap.
a 1996 will also have a camshaft synchronizer

you REALLY don't want that... read on the 4.0 forum and you'll know why.

You are going to need the ON-Engine harness and sensors to match the
harness you use.

It's an ugly job but it's been done before.

this isn't something you are going to do in a weekend.

I knew exactly what I was doing and if left utterly interrupted it
would have taken me 7-10 days, though I intentionally made my
conversion harder because I rewired the ENTIRE truck, added dual tanks
a new audio system retrofitted cruise control AND I used a 1993 explorer engine and wanted to also use the explorer power distribution system...

Basically I REALLY complicated my life while doing the conversion in the name of "elegance" (something all true engineers can't resist)...

for example my 1993 Explorer donor (I bought the entire explorer and cut it up)
had ABS and though I didn't want ABS the two relay sockets in the load center
for the ABS system AND the wiring to them were "useful" for my Fog and Driving
lights as well as my high powered comm radio(s)

I wanted all my relays "on top" so I could pull one quickly if necissary...

AD

 

[AllanD]

"HEGO" = Heated Exhaust Gas Oxygen

the oxygen sensors, 1990-92 use a single in the Y-pipe "collector", the '93-94 use duals, one for each cylinder bank, '95-on use three, adding a "cat monitor"
to verify Catalytic converter function and efficiency.

you just need the earlier Aluminum upper intake, the '95-up PLASTIC upper intake has several ports
that you don't need, that are difficult to plug and '95-on use different sensors...

the lower is different, but different in a good way.
the '95-up adds that thermal insulator between the
intake and the fuel rail.

you will need to change the injectors, the '93-up injectors don't "play nice" with the '90-92 computers.
the later injectors have a higher flow rate but tattoo this on some visible body part: "the wrong ammount of fuel is the wrong ammount of fuel"

the 1993 wiring has some distinct advantages
inthat the relays are all "up top" in the load center box, you get twice as many maxifuses as well as some smaller "micro" fuses AND you get a couple spare relay sockets.

If you go with a 1993 harness and an "ANY1" coded computer you don't need to remove the fuel rail or swap out the injectors
However the 1993 wiring and computer use dual oxygen sensors and that requires a different Y-pipe
OR getting the proper bungs welded into your exsisting Y-pipe.

a 1993-94 Ranger harness won't do you much good because of where the Rangers placed the computer
in the DRIVERS side firewall accessed by removing the inner fender... a really stupid place that Ford only used for two years. and scrambled engine bay layout.

the 1993 Explorer maintains the same layout as earlier explorers just with more "complication"

Avoid a 1994 harness like it has AIDS.
you DO NOT want either EGR (not that EGR is a "bad thing" but the sensor that tells the PCM that the EGR is functioning correctly is a failure prone POS)
or Sequential injection.
"sequential injection" is one of those things that sounds like a "good idea" but the electronics necissary to support it are the problem.

Read the 4.0 forum about camshaft synchronizer problems (and price) and you'll never willingly have one.

I have an '87 into which I swapped a 1993 Explorer engine and harness, but I did use some 1994 elements... in particular the 1994-up alternator bracket and tensioner which is a superior design to the 1990-93 bracket and tensioner.

The 1994-on tensioner looks harder to access than the more exposed 1993 tensioner, but this appearance is deceptive....

Hi Allan,
THANKS for ALL the info!
WOW!
I have a question...what is HEGO?
You typed: "AND it's single HEGO which will "play nice" with 1991-92 management."
ALL the rest makes sense...
Do I need upper AND lower intake or are the lowers the same?
I have the '88 Ranger EVTM already,+ the '96 Ex EVTM too!
I WAS willing to figure ALL the unnecessary wires, thinking like you it would be great to have all the extra circuits for "stuff". But a 91-94 harness just sounds SO much easier. And of course, I will seek a 91-92 first!
There is a '93-94 wire loom/ECU/Injectors/upper+lower intake...on this forum now. Should I jump on it, or keep looking for a 91-92 setup?
Again, thanks for ALL the info.
I REALLY scored finding this forum!
I am going to list the misc parts from the donor '96 EX later today. Hopefully, I can help out another soul!
Thanks again, Brian/milehibry

Do understand that the EASIEST harness for you to deal with would be a 1990-92 Ranger harness.

the main difference in an Explorer harness is that there are distinct wire routing differences for things not related to the engine or management. Power windows and doorlocks, rear wiper rear window defogger etc....

This really stirs the pot so to speak when trying to understand the differences...

swapping a 1990-94 4.0 into a Gen1 (85-88) with EFI isn't the most complicated swap and you can top it by swapping a 1990-94 4.0 into an '83-84 with a carb, it's about as complicated as things get... unless you really wanna swim upstream by swapping an EEC5 engine into a gen1...

My swapping a 1993 engine and harness would have stumped many people, but I learned wiring by wiring military aircraft
components and complicated control cabinets.. so it really wasn't THAT complicated... for me...

It helped greatly that I had all the relevant EVTM's
infact I have 1984-1994 and some I have a "dirty copy" and a "clean copy" of... Fastpakr has seen my tech library...

The I needed FOUR for my swap, 1987 for the Truck,
the 1988 for part of my cruise control, 1993 for most of the rest of the truck & 1994 only for the A/C wiring.
I built my truck with 1994 A/C because it's designed from the beginning for R-134a.

Some people read porn in the bathroom, I read technical manuals... atleast until I have them memorized...