Truck: 1990 F-250 4x4 with the 5.8L EFI
Project: Swap the original OBD computer to the newer OBD2 from a '97 or newer
Goal: Being able to upgrade and tune the computer on the fly with the use of a power programmer like a BullyDog or Diablo Sport. Would also allow me to adapt a supercharger system off the newer Lightning to the 351W. Also getting live data streams.
Alright, I am brand new here. Love the site though, so I thought i would get some thoughts on my new project. Any input would be much appreciated.

 

i realize that you just explained your reasoning, but....WHY???? if your dead set on it....have fun.

 

x2. An OBD1 mass air upgrade would be a lot less complicated and deliver the same results, only difference is you won't have a handheld tuner you'll have to use a laptop tuner(Moates/Tweecer).. not that you'll really need one until you get a blower.

 

It has been done before, but as noted here and here: OBD II Gen I it may not get you the desired results for the effort you put into it.

I have thought about the exact same project as you. But as reasonable thinking sunk in (read that as $$$ needed) I would rather go with a Moates before putting in the effort to do a OBD-II swap.

To each their own, so if you want to go OBD-II that is your choice. Maybe you can teach us "old dogs" new tricks.

 

It would be a huge amount of work to convert to OBD-II for not a lot of gains.

 

waste of time and money for very little gain.

it would be a better investment to buy a new lightning.

good luck if you try it.

 

Well heres the deal.....i got a free tuner its a diablo sport. and i have recently located a '98 f-250 4x4 with the 5.8 for $250. This way i dont have disassemble the e-brake and kick panel just to get to the computer. This also takes out all the stupid smog system i hate with out throwing codes or having to plug it all off. This '98 doesnt have air-injection smog or the old school EGR valve.....plus it has JBA headers, and a bunch of auto-meter gear. Throw all of this together and i get all my upgrades for down the road when i add a supercharger. The total $250, and about a weekend of work.

 

Well i would like to note that i dislike the lightning as a whole, save for the supercharger system, i am an offroad 4x4 fan, and that truck is not. I got the f-250 for the reason of the 4x4 and i work in construction. so i need a good workhorse.

 

This line of reasoning makes no sense. You have to remove the OBD-1 computer to "upgrade" to OBD-2, so if you're taking it out anyway it's going to be far easier to simply add a module to an OBD-1 computer and plug it back in than replace the whole wiring harness and install an OBD-2 computer.

If you haven't bought a truck yet and you're set on using your free tuner just go find a newer truck that is compatable with it, otherwise sell the Diablo and put the $$ towards upgrading this truck.

 

They quit using the 5.8 in 1997. A 98 will have a 4.6 or a 5.4
The 5.0 and 5.8 OBD2 isn't a real OBD2 anyway. It is pretty much OBD1 with a OBD2 connector. They do not use downstream O2 sensors and you can not look at live data like you can with all other OBD2 systems.

 

like conanski said, what you want to do makes no sense.

 

First, i apologize.....the donor truck is a '97.......i was looking for parts for my buddies '98 when i wrote that. Yes, i already have the '90 4x4. I have yet to find a module that will let me use a tuner. Not to mention i have never had good luck with an piggyback add on module in a truck. Can someone elaborate on its not a "true" OBD2, ive used tuners and the like on a 97 f150 i helped dyno. It worked just like the newer OBD2's.....so what am i missing with that?

 

97 F150 doesn't have a 5.0 or 5.8 it has 4.6 or 5.4. So it is a real OBD2. I am not saying an OBD2 tuner won't work on 5.0 and 5.8 I'm just saying it isn't truly OBD2, just uses an OBD2 connector. If they sell a hand held tuner for 5.0 and 5.8 OBD2 then I'm sure they will work.

Edit: i guess I should say it isn't conventional OBD2. To me it isn't real OBD2 because it has an OBD2 connector but everything on it works like OBD. You can't look at sensor data and it doesn't have O2 sensors after the cat. Every other OBD2 has O2 sensors after the cat and you can look at sensor data.

 

Unless the '97 F250 is a california truck, chances are that it is still OBD-I. All OBD-II trucks will have downstream O2 sensors. The earliest OBD-II might not be capable of real time data monitoring or be able to use a flash tuner, but there is no quasi OBD-II; it is or it isn't, there's no middle ground (at least in these trucks).

 

My 96 F250 is OBD2 and does not have a downstream O2 sensor. I work on cars and trucks for a living and have seen many of these trucks like this.