2.9 to 4.0 swap. General info and lots of help!

[Rangerous42]

To all of you who are planning on doing the 2.9l to 4.0l swap, or have already done it and are still working out all the bugs, I may be able to help. I have a 1989 ranger fully loaded 4wd 5 speed that had a 2.9l in it and i swapped in a 4.0l from a 94 ranger. Ive had it running for about a week now and so far ive got everything except cruise control, a RABS light, an occasional check engine light, and a rare and random stumble/ cutout during acceleration. Here are a few tips which im sure most of you know but, just to back them up i guess.

-The ticket is to get everything you are going to use from one car. For example, I got a engine from a 94 ranger with EGR but got the engine wire harness, complete engine bay wire harness, ECU, Cruise control Module, airbox w/ maf, EDIS module, barometric pressure sensor (located on firewall near the passenger wiper, most vehicles have a cover where it should be, so it depends on the vehicle you are pulling your parts from.), radiator, throttle cable, and a few other knick knacks from a 92 explorer with a 5 speed.

- I learned that it really helps alot to know a thing or 2 about wiring, and to have all the most detailed diagrams possible.

- Since everyone knows EGR is a bitch that just gives you more codes, I chose the 92 so i wouldn't have to deal with it. Luckily my 2.9 had a plug in the manifold where the main EGR line went into the 94 4.0l, so i just dumped that line and capped it off. as for the line going to the intake manifold, i just had my machinist fabricate a plate to cap it off and it was good to go.

So yeah, like i said, i have conquered many areas that i did not think i could (with the help of my brother in law) and im just letting everyone know that im here to help however i can in making your 4.0l swap as easy as possible. Because alot of you know how SHITTY IT CAN BE to try and leave the line or cruise uphill on the highway (primarily with a lift) and having to drop that 2.9 into 3rd at 5500 rpms on a 250k motor just to maintain 65 (at least for me). So i am REALLY loving the absolute shit out of this 4.0l.

Feel free to PM me with any questions!

 

[AllanD]

By combining parts from a 1992 and a 1994 you created some of your own issues.

The 1990-1992 4.0's are basically the same with only minor calibration changes

1993's use a slightly more advanced form of engine management called "Active Data Link"
which enables the proper kind of scanner to actually read real time sensor outputs
rather than preprogrammed "pass/fail" indications.

Part of that change was Dual HEGO sensors, one for each bank.

and Different (not necissarily "better", just different) injectors.

1994 added a cam position sensor for SEFI, SEQENTIAL injection
The Cam "synchronizer" is not only failure prone but technically
demanding to replace as well as expen$iv....

and there's the EGR you already mentioned.

The problem with EGR is not the EGR, but the sensors that tell the computer it's working as commanded AND the programming of the computer to do a complete ape-shit overreaction to any error indication...

there are also additional complications introduced by the differences in wire routing
between Rangers/Bronco2's and Explorers...

that all being said I used 1993 Explorer engine and wiring harness, the
only parts that were "something else" were the A/C harness from a 1994
(I wanted the HP cutoff switch that the Factory R134a system had)
and a cruise control that was cobbled together from a987 bronco2 and 1993 Explorer parts (everything under the hood is 1993 Explorer, everything under the dash is 1987)

I specifically chose, then bought at auction a 1993 explorer as an organ donor
because of the exact combination of sophistication (Active data link) and simplicity
(No EGR or SEFI) of the engine & Management
because going wiht a simpler 1990-92 setup was of no benefit to me...
As I was putting it all in a 1987 Ranger none of it was going to be "plug & Play" anyway....

But I also wanted that larger 1993 Power Distribution box to clean up the power supply to my auxiliary lights and communications radios

the only Bug I have not killed is the A/C Wide open throttle relay...

If I crank the engine with the A/C on or use WOT with the A/C on the relay trips out like it is supposed to, but the relay coil NEVER de-energizes and the key must be cycled to off to restore A/C function (I replaced the relay with a short jumper wire across the
relay socket, so I have no A/C-WOT relay...

I have helped several people swap from 2.9/3.0 wiring to 4.0 wiring in Gen2 Ranger/Bronco and with the proper wiring harness (a Ranger harness) the job takes only about 2-1/2 hours.

To do the same job on a gen 1 takes as many WEEKS to do it right.
a whole lotta splicing and harness splitting going on....

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