Computer & harness from SOHC to OHV ?

[chevyh8ter]

I'm not concerned about the engine and trans fitting.
Just wondering if the 2nd/3rd gen computer system/harness will work with the older engine.
I've seen it the other way around. Someone swapped a newer over head cam engine into a old 90 Ranger with the old computer and harness...so, will it work the other way around too ? I just like the older push rod motor better, and my 91 Explorer may need a new computer and harness soon.
Thanks for any help !

 

[chevyh8ter]

Maybe I should re-word my question.
Has anyone swapped a OHV engine to a 2nd or 3rd gen with the stock Over Head Cam harness ?

 

[Turdle]

Well,
The 91 won't work with a 94 harness, let alone a 95 up

your 91 has one 02 sensor, and the 2nd gens have 2. 94's also have 2 o2 sensors, cam sensor and egr.

There is also a cam sensor on 2nd gens. 2nd gen pcm controls the trans so it will want to see that.

 

[boominXplorer]

It would be beneficial if you upgraded to a 5r55e trans with obd2 computer from a 98-00 ohv truck. If your trying to keep your current al4d trans then it's best to stick with what you got.

 

[chevyh8ter]

I have a 5 speed.
The o2 sensor I can add.
That leaves the cam sensor. I'm guessing the crank sensor would not be timed correctly since the cam is smaller which would spin more RPMs. Now I'm wondering if anything can be done about that ?
I know it seems easier to just stick with the stock computer, but I've already replaced the computer once and it wasn't easy to find. Apparently Ford change the computer every year on the first gen models. Not only that, I notice there was a couple computers with different part numbers for the '91 5speed manual. In other words not just different from automatic & 5 speeds, but at least 2 or 3 for the 1991 5-speed alone.

 

[boominXplorer]

Usually in each year there are 2 or 3 different computer codes with the same wiring setup. I am not sure about the early years but it does apply to the later years (96+). The factory tune strategy might slightly differ but the electronics it uses might be the same. I've used an EQE4 in place of an EQE3 in a 00 and I've tried 2 different 97 computers in my V8 swapped ranger (XDT2 and XDT3) and both worked exactly the same.

Since there's no programming involved I'd try any 91 5speed computer and see what happens.

 

[chevyh8ter]

Maybe thats whats going on then.
Really I'm just trying to see what combos are possible since I have 91, 95 sports with OHV and a 91 Bronco II thats getting a 4.0 swap.
So, 20 yrs from now I'd like to have easy access to parts without having to rely strictly on 91 or 95 parts (Versatile). Building it in my head first sort of thing.
Thanks for the reply...I appreciated it !
EDIT:Oh ..just FYI..the 91 and 92 are completely different than 93+.
91 has a barometric sensor and 92 doesn't !

 

[Turdle]

Yup. If you read thru my 93 thread, it took 3 harnesses to find the right one for my california automatic with sequential fire injection , cam sensor and 2 o2 sensors.

Other 93's had a completely different configuration. 94 would not work because it has egr.

 

[boominXplorer]

Yeah there is batch fire and sequencal fire in 1st gen depending on year. 91 and 92 should be similar on spark fire but emission controls are different for each year and area depending on where you are (cali vs federal emissions)

 

[chevyh8ter]

What the **** ?
Goddamn !

 

[Rhett]

What the **** ?

My thoughts exactly. Here's a thread about the differences between years 91-94:
http://www.explorerforum.com/forums/index.php?threads/differences-between-years-1991-1994.447665/

 

[chevyh8ter]

So as far as I can tell. It may be possible to use a 94+ push rod motor with the later Over Head Cam harness & computer because it has provisions for the cam sensor (EDIT: & EGR). I've seen that the cam sensors changed from 94-95 then again in 96 and 98. With that in mind, I'm wondering if it would be as simple as modifying the plug in order to get a signal ? Other than that, I don't see any other red flags that may prevent the swap.

 

[chevyh8ter]

Its the future...Mega Squirt !