I was wondering the same thing about the OBDII thing. I'm not really sure why anyone would subject themselves to the wiring nightmare of an OBDII computer without any benefits in driveability. OBDI handles engine parameters pretty well and is capable of supporting untold amounts of horsepower. Plus it's well-known (and well documented) and parts are pretty damned cheap for them.
I would think the only real reason to do this conversion in lieu of the simple OBDI swap is to gain an integrated TCM/ECM package? Is this one of those "because I could" projects? If so, more power to you.
I'm not trying to rain on your thread mind you. This is one of the best tech threads I've read. I'm just curious as to why you would choose to do this swap when adding the complexity of an OBDII doesn't bear any advantages vs an OBDI that I can see.
Good luck with this. You are a braver man than I am in that regard. I look forward to see your progress.
$500 Bucks! ;D (engine, tranny, computer, harness, etc)
The main reason is the TCM/ECM integration. The emmissions system in very simple compared to the older stuff. The only external components are a solenoid opperated canister purge valve, vent valve, and a pressure sensor in the tank. The 2 extra oxygen sensors (cat efficiency) are self contained within the engine/tranny harness.
Another good reason is relitively new components. 2000 Explorer, 60 some thousand miles. Newer technology. Better relaibility. Easier to trouble shoot. Better availability in the salvage yards, ...
OBD II is a very powerfull diagnostic, easy to use, and inexpensive. Developing an understanding might avoid those $100/hour trips to the shop for your other vehicles.
Even though it's not required in Colorado (yet), it gives me a good feeling to run a 40 year old vehicle with 2000 emmissions standards. I don't see it as that much of a hinderance. I guess running a cat and vapor recovery system doesn't bother me that much.
I'm hoping for drivability and efficiency similar to my 5.0 98 Explorer. We hope to use it for road trips, camping, and trail riding. Plus anyone such as a repair shop or future owner that can work on a 2000 Explorer will be able to maintain it as its all stock configuration. Parts availability is also better.
Sticking a OBD I system on an newer engine pretty much limits you to a 5.0L. Many people that do these conversions are running in the blind as far a truely understanding issues leading to poor drivability and efficiency. It also opens up the possibility of newer, lighter, drivetrains. More and more information and products are becomming available to tune and flash program the OBD II computers.
It's not really a daunting of a task as it might appear. I find it a fun challenge. This is my second conversion. The first was an OBD I using the stock harness. This one is really much cleaner and straight forward with a little understanding. I have an engineering and control systems background. I'm willing to share what I've learned so others might benefit.
Dave...