whats all needed to run the 4.0?

[Bigred89]

hey guys so im throwing the idea around to build a smaller tube chassis rock crawler, the idea is to use a stock 4.0 ohv from my 98 sport which has the manual 5 speed. my question is what must i all need to make the 4.0 run properly, i.e. needing the pcm? would i need any of the fuse boxes? must i run all the O2 sensors? the idea is to only have the bare mininum for whats needed to properly run this motor. Aftermarket tach and gauges would be used and maybe a push button ignition.

 

[410Fortune]

Good question! The answer is most of whats attached to the engine harness needs to stay, the PCM and all the components
Yes you should keep at least the upstream 02 sensors, the downstream, you can use a cheater...but to me its like why? Just install a bung and run the 3rd sensor.
The charcoal canister and the EVAP system can go away as long as you keep the canister purge and canister vent solenoids plumbed in or use resistors to fool the pcm to thinking they are there.
Of course for 98 you will need a VSS from the rear axle or the PCM will freak out when it does not see a speed sensor signal
98 has PATS secrity so you will need to keep the ignition halo, key, pats module to again make the PCM happy

So yeah basically we can make a 4.0L OHV run in a VW bug if you want to, no problem
You can use aftermarket gauges and push button start...
if you can do some tuning you can tune out the pats and some of the emissions stuff, stripping it down even more.

If you really want to strip down that 98 engine and get it to run without all the pats stuff a 96/97 Explorer/Ranger PCM would be perfect although those engines have the EGR and a cam sensor, the 93 Computer is awesome because in 93 there was no EGR or cam sensor, but 93 is OBDI so not as good performance wise.
You do have options!

 

[Bigred89]

Ok awesome, I appreciate the response!

 

[imp]

@410Fortune OBD-I would indeed be the easiest way to go, IMO. imp

 

[Bigred89]

So if for example if I wanted to go the 93 ecm route what would I all need? The ecm and wiring harness from a 93 4.0? And when you say the OBD-1 isn't as good performance wise what do you mean? Electrical and computers is a weak spot for me so if you don't mind explaining that a little that would be good, thanks

 

[410Fortune]

All computers were OBD-1 or on board diagnostics system #1, in 96 all vehicles were required to goto OBD-2
In computer terms it means eec-iv VS eec-v
There is a HUGE difference in performance between the two, not necessarily from the drivers seat but from the engine management point of view. Lets say a OBD1 vehicles computer may have 16 fuel/spark/air maps to choose from, a OBD2 computer would have more like 16000
So its like your cricket flip phone from 1998 vs the Iphone X from 2020, HUGE difference

So with that being said the 93 OHV PCM is a great little computer and they work very well. To run a 98 OHV engine with a 93 5 speed computer you will need the computer, the wiring harness, upper intake, fuel rail, mas air flow sensor, exhaust downpipe(Y pipe) and several sensors from the 93 engine and maybe more. It all depends on what you are starting with?

Do you already have the 98 truck/engine donor? What exactly are you trying to do here? I can make a 98 engine work in a 93 or I can make a 98 engine run on a stand or I can make a 93 truck into a OBD2 compute truck that runs the 98 engine...I mean there are lots of ways to build a project, we just need to know what the heck you are thinking of doing here. If you already had a complete 93 explorer as the base for your buggy then it would be really easy to use the 98 longblock in there and start chopping up the vehicle to turn into your buggy.

 

[Bigred89]

Well I have my 98 two door that's in my avatar picture so I have everything available, basically I'm throwing the idea around of having a lighter buggy and using my 98 as a donor since I have solid 44/8.8 axles and a doubler, basically everything I need to switch it all over to a tube chassis. So honestly a stand alone would be more ideal since all I'm after is just making sure the motor runs properly. I live in Minnesota so the explorer itself has seen better days with winter salt, just lots of rust on the underside

 

[410Fortune]

I like tube w fiberglass bodies
I like the way ranger guys back half their trucks and then remove the front half too, leaving basically some frame rails from the front bumper to the back of the cab, then everything else is tube.....easy to work on, light and functional. Can hang fiberglass to make it look like a truck/explorer/f150 whatever you want. Nothing like a fully linked long travel 4wd ranger based truck to get the juices flowing, whether its mud, rocks or sand they are super awesome.

But you will be exposed to the elements and the noise, trucks are quite noisy going down the road when there is no body, wheel wells, floorboards, and noise dampen material
The only thing I don't like to see is all these cobbled together rigs with half inside cage, half exo, some weird bends to try and clear the old dash, mount some old seats, tie into this, tie into that with bars going everywhere through the hacked up body...etc etc too much weight up high hurts your cause. Exo tubes take too much metal to reach their destinations
Either do tube or do frame rails, but dont do some and bits and pieces, plan it out do it right!
That said there is something to be said for a simple A pillar/B pillar interior cage.
A stripped down sport body with a simple roll protection is probably the way I would go. I like the creature comforts and we do alot of winter so I keep as much ""cab" as I can..its also cheaper and probably a heck of alot easier....plus if you screw it up, go get another sport body
I mean I am looking at fixing up my BII rust.... I can get a rust free BII body for like $300... lol at some point you just swap the body

@RangerX has a really nice simple driver protection cage that i've always liked, maybe he will share some pics

 

[Bigred89]

I also like when guys back half a ranger and four link the rear. My thought was buying a chassis from fabn801.com, it's a bare bones chassis but it's a solid starting point but the more I think about the more work it really starts to seem so I was also thinking of doing some sort of back half on my explorer and doing a rear four link. I mainly just want to make it as light as I can because it's just easier on drivetrain components and also I have a 2000 expedition as my tow vehicle, runs great and very clean and I don't want to get into the diesel side of things so having a lighter rig benefits in a few areas. I also find it hard to believe that a two door sport weights 3700 pounds according to my Google search. Is that accurate? That just seems heavy to me for what that thing is in stock trim.

 

[410Fortune]

yes around 37-3800# for 4x4 sport
the 4 doors are like 4400#

Giant motorsports makes a nice link kit
There are also some really nice leaf spring and shackle setups that work well on the back of a RBV, the "link killer"
they call it, less money, less work, still keeps your tires planted on the ground. The link setups are awesome for go fast guys who need their alignment changes to be minimal as they mob through the whoops, leaf spring setups are cheaper and lighter =. Lots to think about

Your 2000 Exped is it a 5.4?

 

[Bigred89]

Yea you do make a good point about leafs being lighter and more simple, I need to think about it. It is a rock crawler mainly and the rear mono leafs flex pretty dang good. My expedition is a 5.4 yes with 155000 on it so that's not bad since most of them are around 200-250k miles. It pulls my explorer just fine, it's a tat poochie on hills but it's not bad. Considering some bolt ons to help that 5.4 breath and flow a lil better also.

 

[Bigred89]

Does anyone have the diagram of the pin connector for a 98 4.0 ohv explorer with a manual transmission?

 

[Stic-o]

Yea you do make a good point about leafs being lighter and more simple, I need to think about it. It is a rock crawler mainly and the rear mono leafs flex pretty dang good. My expedition is a 5.4 yes with 155000 on it so that's not bad since most of them are around 200-250k miles. It pulls my explorer just fine, it's a tat poochie on hills but it's not bad. Considering some bolt ons to help that 5.4 breath and flow a lil better also.

Have you done the Y pipe? It's a huge difference on these 2v. Woke up my V10 when I had it.

 

[Bigred89]

Have you done the Y pipe? It's a huge difference on these 2v. Woke up my V10 when I had it.

No o haven't done anything to the expedition, bone stock but that's good to know. Thanks

 

[410Fortune]

I have the wiring book for a 2000 here at my desk, I can take a pic of the manual trans wiring and send to your phone? PM me your number

 

[410Fortune]

the dang 2000 book I have does not cover the M5od 5 speed, only the 5r and the 4r, what the heck? No 5 speed option in 2000 Explorer? Thats BS! Wait no more OHV in 2001 maybe that's the reason?
Anywho I did some online searching and found some 98 starter system wiring info for you and sent a PM
Let us know if that helped!

 

[Bigred89]

Haha dang Ford and always changing everything after a few years! I ordered a Haynes manual for the 98 and it said it has electrical stuff in there so we'll see if that's in the book plus it'll just be nice too have a book like that anyhow for when you need to know little stuff like this

 

[Bigred89]

Well I did some research and there's a place in Florida called autocomputerperformance.com and they can pretty much delete anything you want on your ECU/PCM including the PATS system! They can also delete emissions stuff and also do some performance tuning and a lot of other stuff so I sent them an email to get some sort of price range to make my computer a stand alone unit