OBD II conversion?

[seth247]

has anyone ever converted a first gen ohv to run on an obd ii computer? (say from an sohc engine)

I figure since you can run a sohc on an ohv's ecu then maybe it could happen the other way around.

 

[Blacksheep Josh]

if you could, it'd take a lot of work.

 

[seth247]

I don't know. It might be as simple as splicing the wires from the eeciv harness in to the eecv harness. And then somohow getting around the fact that the engine has no cam position sensor. And maybe welding in a few more o2 sensors.

 

[seth247]

I tell you if I had another ex I would try this right now just for the heck of it. I could always undo it if it doesn't work.

My main worry is that that the eecv won't know what to do with the ohv. Its parameters are set for the sohc but maybe with a tune to keep the a/f good...

 

[wyochimneysweep]

more work then you want. if it needs a cam sensor and you don't have one it would be impossible. why would you want obd2???

 

[CDW6212R]

Tuning would be required if the old engine was not exactly like the PCM model. An OHV PCM from 96+ would likely have no trouble with a 1st gen engine, but the sensors would have to be there. I'd say the big issue would be installing all of the wiring and sensors, especially the dash wiring. The PATS system from 98+ would be harder(tune required), and 99+ has the wrong fuel system.

The only good reason to do it would be for the ability to tune easily with a flasher. That would only be helpful if you had quite a few modifications. Beyond a modest gain of the possible 20hp or so, doing a far more powerful engine completely would be more logical. That points to a V8 and transmission swap, a big project by itself. Good luck,

 

[seth247]

I didnt know theyre were any second gen ohv's. That would make it easier. What are the differnces in the two engines?

Why would I have tonswap the wiring? Its already there.

 

[CDW6212R]

Are you dealing with a 1992 Explorer, listed in your avatar? The pre-95 Fords have no OBDII wiring in them, all of that would have to be added.

 

[410Fortune]

my 1988 Bronco II is 97.5 OBD-II 100%, even the cruise control works.
I had to add a fuel tank pressure sensor and do a HELL OF ALOT OF WIRING
to make it work, but the end result is actually pretty simple

the obd-II computer to truck interface is basically the same as OBD-I, there are like 16 wires the truck needs a signal from (dash systems, gages, lights, switches, etc)

Brett recently did this backwards, hes running a 2004 SOHC engine in his 93 Explorer sport using the 93 OHV computer..

anything is possible when you sit down and map out the wiring

 

[seth247]

exactly. I'm a trained industrial mechanic so I now wiring thats why I was considering it. Nothin is impossible. But now that ive decided on the v8swap (thanks 410 fortune) I won't worry about this.

Maybe some other day when I get a bronco.

Thanks guys for the help.


(woohoo 400+ posts!)

 

[CDW6212R]

Good call, the V8 swap is the best, if you can raise the compression with a different reciprocating assembly. That will give you the best chance at decent fuel mileage.

 

[seth247]

I plan chargin' the v8 so do you think it would be best to keep the stock comp. On a 302 (just realized I don't know what it is.)

 

[CDW6212R]

The OBDII in the 96-01 Explorer's is wonderful for all modifications.

 

[jah81592]

Why don't you go with a harness from an OHV in a 1996-later Ex? This would be the easiest. The only problem would be is you would have to have a tune to turn off the controls for the tranny or your CEL will light up-quickly! The SOHC harness won't work, the cam position sensors are different (the way they read, and this cannot be corrected in the tuning) not to mention the style knock sensors are different, I could go on and on. Swap in a SOHC v-6, power to weight ratio would be better and reduced weight never hurts. The engine will sit right down in your motor and trans mounts. If you were going to swap harnesses anyway, this would be the simplest swap. The sohc is a stout engine.