When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
We put a 4.0L in my friends B2. But his uncle screwd up the wiring. We put the 4.0L harness in the dash but it wont mate with the engine harness, as if it is still the 2.9L harness. Any Ideas?.... We are trying to figure It out.....
so let me get this straight. You have the 2.9l harness on the engine, and the 4.0l harness in the dash? Sounds backwards to me. If that's right then I might pull out the you're fubar remark. If it's backwards then you just need the computer to get the engine running, and the rest of the cabin can run off a seperate 12v send, you don't need the 4.0l harness for that.
see i always rthough there where two harnesses in this truck. One for the engine controls....and one for all other 12v things, such as lights, or blower motor etc...
Soo what i thinkyou need to do is leave the 2.9 non-enigne harness alone...and ditch the 2.9 engine harness an ecu, and mark the power supply and other leads feeding that harness and simply swap in the 4.0 harness.
Remeber, if you ever decide to remove a harness from any engine...its ALWAYS a great idea to get tape and tag every wire and/or connector, as a good reference when you need to re-connect it back up
You need the complete 4.0L engine harness and 4.0L CPU. Major differences between the two engines (sensors included) not counting one is a DIS and one is Dist./TFI. There has to be 60 different wires for the 4.0 CPU, I can't see splicing all that mess and still have it be reliable, not to mention some wires are OHM based and will be effected by a splice. Same type of deal with the 02 sensor harness for a 4.0L, you can't splice it because the 02 will not travel pass the splice.
You need the complete 4.0L engine harness and 4.0L CPU. Major differences between the two engines (sensors included) not counting one is a DIS and one is Dist./TFI. There has to be 60 different wires for the 4.0 CPU, I can't see splicing all that mess and still have it be reliable, not to mention some wires are OHM based and will be effected by a splice. Same type of deal with the 02 sensor harness for a 4.0L, you can't splice it because the 02 will not travel pass the splice.
They're actually pretty close and with some re-pinning and the addition of a couple wires the 2.9L harness would work just fine. Of course you do still need the 4.0 computer. Now as far as splicing an O2 there is nothign wrong with that at all. All Universal O2 sensors are spliced in and there's no problem with them.
Go to Auto Zone online and pull the wiring diagrams for both the BII and the donor vehicle the 4.0 came from. That should give you the info needed on what to repin and what to add. It will take some time to chart it out but it's kind of a must do thing because most likely your doner vehicles harness will need some splicing to get it to work too.
Thanks guy's, Well I went over last night and figured it out. The 4.0L harness was on the engine, but some of the 2.9L was in there but not hooked up. So I got it out of there.
I didn't help put in the engine. It has been to about 4 different places and knowone could figure it out so they had it pretty messed up.
The main problem was the harness going down the frame to the full pump was 2.9L. So I just spliced them together . Turned the key and she fired write up. Sounds sweeeeet, Now I just got to get the dash back together. I'll try to get you guys some pics.
Even though I own 2 Early Bronco's The b2's Are sweet!
Last edited by earlybroncoboy; Apr 4, 2006 at 09:43 AM.
Im contemplating the same thing myself my 93 exp has a bad trans and transfer but a solid 4.0 I have located a 90 BII with a 2.9,5speed and the motor is bad. Im guessing the closeness in model years might ease my troubles. Any one have a comment or suggestion? I want to use the BII Trans and transfer the exp is an auto.
CamCraft actually makes hi-performance cams and sells hi-performance refitted world products aftermarket 2.9 hi-performance heads. TS Performance makes/sells EEC-IV / EEC-V compatible performance chips, which you can also have tuned/programmed for a modified or stock engine/drivetrain. This stuff, however, is not for the faint of heart (or pocketbook/wallet/checkbook/etc.)
I found both of these via Google and this site.... needless to say, more research and careful plannning will end up with my project starting sometime in the next decade... er, year or two haha
Also, I believe Competition Cams (http://www.compcams.com) sells 2.8 solid lifter cams / kits / parts as well....
Your going to need to get a 4.0 manual transmission ECU (engine computer) becuase if your going from an auto to manual, the computer thats programed for an auto trans will not work. And visa versa...
Yes!, surprisingly enough though, you can use the bronco II transfer case and transmission, everything bolts up to spec as it would in the explorer. Altough some people have told me that the 2.9 5 speed trans cant handle the 4.0 and may gernade on you. Others told me it works fine. If i where you, id look around for a good 4.0 5 speed trans, just to be on the safe side.