88 2.9 swap to 4.0

Iker316 · Jul 15, 2015

Ok, 4.0l I bought has been rebuilt and ready go into Ranger 88 4x4. I have the wiring harness for the engine but don't have ECU. First question; can I just go and find and ECU from a '99 explorer? (we think the engine came out of and Explorer). What will I find behind the ECU from the dash side? What will I need for sure? I don't plan on changing the dash but will if you tells me it will be hell with out it.

this should be a fun vacation project starting next week. :yahoo:

RonD · Jul 15, 2015

1999 Explorer could have the 4.0l SOHC engine(Rangers 2001 to 2012) or 4.0l OHV engine(Rangers 1990 to 2000), transmission bolt pattern is the same, SOHC will have an extra hole.
So first thing is to find out which one you have

If 4.0l OHV then I would go with an ECU from a 1990-1994 4.0l, these are OBDI and do not require as much wiring.

1995 and up Rangers or explorers used the new computer(OBDII) these require three O2 sensors, one on each bank and an O2 sensor after the cat converter
In '99 they also had Returnless fuel system.

ECU's also come in automatic trans models and manual trans models, you need one that matches what you will be using in the '88

Iker316 · Jul 15, 2015

Thanks for the reply. It is a 4.0L ohv.

Wouldn't I need to get OBDII because the engine has all the sensors? I thought there were some other O2 sensors besides the exhaust.

Why would I need to make sure it is Auto or Manual trans if the trans doesn't hook to ECU? or is it expecting it to and won't run well without it?

RonD · Jul 15, 2015

If you get an ECU from an automatic and don't have an automatic ECU will turn on the CEL(check engine light) and it will never go off, not a big deal unless you actually do have an engine problem then you won't know it until engine doesn't run right, so no "heads up" about a problem.
ECU would also idle engine higher and might hunt for idle now and then

ECU for a manual when used with automatic won't be able to lock up torque converter or operate 3-4 shift if trans has that.

Yes if your wiring harness is from a 1999 then it will be OBDII and you would need an OBDII ECU
OBDII needed just the 3 O2 sensors, 4 if you have dual exhaust or if ECU was from dual exhaust vehicle
OBDI needed just 1 sometimes 2

adsm08 · Jul 15, 2015

Stick with an early 4.0 computer, 90- 92, and the same year harness. Most of the sensors are irrelevant back then and it will make all the wiring, especially the wiring to keep your dash, much easier.

Iker316 · Jul 16, 2015

So I was reading some articles online and one thing that came up is that I'll have to have the ECU flashed because it may have anti-theft programmed into it.

Ever run into anything like that? And how could I flash this without Ford getting into this?

btw, I have a manual so I'll go look for a manual ECU in the Salvage yard.

RonD · Jul 16, 2015

PATS(passive anti-theft system) was added to Fords in the late '90's so if you do go with a '99 ECU then yes you would most likely want to have the PATS "check" removed from the ECU.
This can be done by a programmer with Ford ECU software, $250-$400, this is not illegal if you own the vehicle, programmer's change software all the time to get more power or better MPG.
Ford dealer can do it but won't do that as far as I know, not a factory approved change.

PATS systems use keys with an RFID tag embedded in the black plastic end, this requires no batteries, each PATS key has a unique ID number in this tag.
When you insert this key into ignition and turn it on, a ring(wand) around the key slot sends a burst of RF(wireless) energy, this gives the RFID tag enough power to transmit it's unique ID number.
The ring picks up that number and sends it to the PATS Module or to ECU with PATS module built in.
That number is compared to a list of up to 8 numbers/keys that were programmed into the system at the factory.
If number is found fuel pump and fuel injectors are enabled, if number is not found or there is no number received then pump and injectors are disabled.
In later systems starter motor is also disabled.
Separate PATS module is "married" to it's ECM, so they can't be swapped around, and ECM needs "trigger code" from module to start pump and injectors.
It is a good system, no real work around.

As adsm08 said, I would look at using older ECU with older harness

adsm08 · Jul 16, 2015

Actually Ron, we can't shut down a PATS system by removing it from the software. There isn't an option in the scanner to remove PATS.

About the only way to do it would be to program the computer with as-built data from a vehicle that didn't have it.

We can't even over-ride the PATS system to start a vehicle that has an issue with the system.

RonD · Jul 16, 2015

What?
I big shop like that and no BFH(big f*ing hammer)

LOL

Good to know, thanks for the update

Iker316 · Jul 16, 2015

so with that then I would need a different ignition and key correct?

I also, won't put the catalytic back on so I would have and O2 sensor issue with a 99. hmmmm, guess I should have put a carburetor on, which means I would have to put a mechanical distributor in.

looks like the 90-94 ECU is about my only choice at this point.

That's why I'm do this project, learning soooo much.

adsm08 · Jul 16, 2015

The PATS system can be overcome in other ways.

You could have everything, including the antenna and a key, tucked up somewhere out of the way. That would get the show started.

I'd still go with the older setup. I want to convert my 87 to OBDII one day, but my biggest obstacle in my plans is space. I wouldn't use a PCM later than 96 for that, because it don't be expecting to be able to talk to a bunch of other modules that I don't have the physical space for. Space is tight behind those gen1 dashes.

Iker316 · Jul 17, 2015

so is the antenna in the ignition? or what does it look like?

Iker316 · Jul 18, 2015

So I was at the salvage yard this morning. How about a 94 EEC will that work ok on the 99? what kind of problems might I have?

RonD · Jul 18, 2015

What is the '94 EEC out of, 4.0l I assume, but automatic or manual, it needs to match what you have

Did original engine have EGR valve or CPS(cam position sensor)

You will need to get fuel rail and injectors from a pre-97 4.0l, it used 40psi pressure
'99 has returnless using 65psi pressure
OR.......an not sure it would work, change fuel pump to higher pressure model and change fuel line fitting on engine end.

Iker316 · Jul 20, 2015

the 94 4.0L is out of and explorer which is a automatic and I'm try to put it into a manual 1988 ranger. the 99 4.0L is most likely out of and AT that I'm trying to put into the 88.

The 99 4.0L does have and EGR and CPS.

I really want to use the ECM out of a 99 4.0L because I have the wiring harness in hand but since this is driving me crazy I think I'm going to go get the 90 4.0L AT.

yea, I read a lot about how to overcome the PATS system, dang what a headache. I'm getting to old for this...

88 2.9 swap to 4.0

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