OBD II Engine/Transmission Swap - The Next Generation

[johnmlebel]

wow thats alot of work. when i do late model swap I use a sniper interface tuner and my pc and eliminate the pats as well as the rear o2's so cats dont have to be run. I could even shut down the egr and various other things that ae not needed then take and run a dyno on it to make sure everything is where it is supposed be

 

[Dave]

wow thats alot of work. when i do late model swap I use a sniper interface tuner and my pc and eliminate the pats as well as the rear o2's so cats dont have to be run. I could even shut down the egr and various other things that ae not needed then take and run a dyno on it to make sure everything is where it is supposed be

Maybe this will explain it: http://noolmusic.com/videos/dilbert_-_the_knack.php

Seriously though, if you have an easy way to use OBD II engines you should write a tech article.

 

[Rlemon]

Hello I'm new to CB. I have just purchased a complete explorer 5.o with distributorless ignition. Is there a made to order harness out thier for this system or is this the only way. After reading this thread I might have to go with a distributor.

 

[lars]

Hello I'm new to CB. I have just purchased a complete explorer 5.o with distributorless ignition. Is there a made to order harness out thier for this system or is this the only way. After reading this thread I might have to go with a distributor.

Rich, as far as I know there are no off-the-shelf harnesses available to let you run distributorless ignition on a 5.0 in a Bronco, either EEC-IV or EEC-V. But it's easy enough to swap EEC-IV ('89-'93 Mustang) electronics onto the Explorer engine. Lots of people including myself have done that, and in that case you can buy a commercially available harness. You'll need to source some parts, such as the PCM and some sensors, but that's easy enough. If you do a search on Explorer EFI conversions on this site you can read for days. Lots of information available.

 

[Dave]

Hello I'm new to CB. I have just purchased a complete explorer 5.o with distributorless ignition. Is there a made to order harness out thier for this system or is this the only way. After reading this thread I might have to go with a distributor.

I hope to put a step by step guide when I get this one done. It's really not as bad as it may seem compared to earlier OBD I systems. At least with the 5.0L Explorers. The factory harnesses for engine and transmission functions are much neater and more self contained. What year Explorer are you using? Are you going to use the transmission also? Is AWD or 4WD? If I pull this off I'll have less invested (excluding time) than I would have to spend just for a shift computer and harness.

Good Luck and keep us updated on whichever way you go.

Dave...

 

[Rlemon]

Hey lars I will email you as soon as I can get back onto ncb it seems to be down. I have been reading the 5.0 threads from the past lots of good reading. I just picked up the motor today and got it home. It's a 96 5.o distributorless. The harness looks complete it has several large plugins I believe they go to the computer, fuse box not sure what else. I need to find a computer on ebay, fuse box if used and other parts I'm sure. I have never done any programing this sounds like the hard part. With all the great info and help on these sites from lars dave and others this should be a fun project.
I plan to put this in front of my c4. I am considering a 347 kit, e303, poss aftermarket heads although the gt40 heads might be a good start.

 

[Broncobowsher]

Hey lars I will email you as soon as I can get back onto ncb it seems to be down. I have been reading the 5.0 threads from the past lots of good reading. I just picked up the motor today and got it home. It's a 96 5.o distributorless. The harness looks complete it has several large plugins I believe they go to the computer, fuse box not sure what else. I need to find a computer on ebay, fuse box if used and other parts I'm sure. I have never done any programing this sounds like the hard part. With all the great info and help on these sites from lars dave and others this should be a fun project.
I plan to put this in front of my c4. I am considering a 347 kit, e303, poss aftermarket heads although the gt40 heads might be a good start.

If you are missing as much as you say you are, it would really be better to do a Mustang EFI swap. The OBDII swap is viable when you start with all the parts. And I use the word viable loosly as we are waiting for the first one to happen. Especially if all you are doing is putting it in front of a C4.

One of the issues is that during the few years that Ford put these engines in the Explorers, they changed a lot of stuff over that time. Adding and removing sensors and completely restructuring the EFI. The parts that you need for the '96 engine are mostly going to be '96 specific parts. And the bad part, the changes don't follow model years. Most of the changes occur mid-year. So even if you find the right year does not mean it will interface with your parts.

If you started with a complete donor then I would say keep reading and see if you can pull it off. But I thnk you are going to be disappointed, spending a dollar to salvage 10¢ of stuff, building a house starting with a roof and finishing with a foundation. The '96 is such prime material for the EEC-IV as it still uses the old sensors and with only stretching a few wires is a plug in. no PATS to work around. Not having to go in and defeat, turn off, trick 2/3s of the sensors, etc.

 

[Dave]

It Runs!

Got it running today. It fired right up and runs smooth.

I built up a test fuel tank to accept the Explorer fuel pump assembly as shown below. The 5.0L Explorer use the same type of fuel pump as the older systems. The PCM controls the puel pump through the fuel pump relay. The wire from the relay goes to the inertia switch and directly to the pump. In about mid 97 Ford changed from a return line system with a pressure regulator on the fuel rail, just like the older stuff to a pressure regulator mounted in the tank on the pump assembly as shown in the picture below. On these systems the PCM monitors the fuel pressure and temperature in the rail. The injector pulses are modified to reflect the current rail pressure and temperature. In both cases its a simple one wire hookup.

If you ignore the mess of wires on the left of the photo which are just hanging from the power distribution box, the right side is the total required to make it run including the communication network. In reality it's a lot less work than the first OBD I conversion that I did.

Next step is setting up a radiator so I can run it for more that 30 seconds at a time. I've got cats and O2 sensors on order that should be in next week so I can get the whole system set up. Several have complained about all of the sensors that you have to turn off and fake out. I'll be using all 4 O2 sensors which only leaves evaporative system. That consists of a pressure transducer in the tank, a canister purge solenoid, and a vacuum solenoid that will be connected and used as designed. The PCM also monitors the fuel level signal (signal that drives the gas gauge) to determin the volume of vapor in the tank to control the purge cycle. I'll diagram all that later.

I am having one glitch. My scan tool looses comunications when I hit the start botton and without a radiator I can't run it long enough to restablish the connection. I think I need another circuit to isolate the starter solinoid.

 

[DirtDonk]

Nice going Dave. Must be those cold CO nights keeping you indoors long enough to get things done.
That Eplorer pump looks pretty straightforward. Did you happen to get a measurement of it's overall length by any chance? Just wondering how well it'll fit into an aftermarket Bronco tank.

Paul

 

[Dave]

Nice going Dave. Must be those cold CO nights keeping you indoors long enough to get things done.
That Eplorer pump looks pretty straightforward. Did you happen to get a measurement of it's overall length by any chance? Just wondering how well it'll fit into an aftermarket Bronco tank.

Paul

12 inches deep would be perfect to give the fliter on the bottom about 1/4 inch extra. Port diameter is 4 inches and the flange is 6 1/2 inches in diameter.

And the money I'm saving by not going out is more than paying for the project.;D

I think exercises like this keep one's mind from getting mushy and I like to feel I'm contributing something to help others.

 

[Dave]

More Progress

The exhaust system showed up yesterday including the oxygen sensors and cats. Hooked up the test cooling system and cranked it up. It really runs nice! I got it running without any diagnostic test codes. (DTCs) I'll have to do some cut and paste work on the exhaust system but that should be fairly minor. Mostly to get the cat in the crossover pipe tucked up a little tighter. I'm just about ready to wrap up this stage and get the chassis ready to accept the engine and tranny. More later. Dave...

p.s. This stuff is fun to play with. It's really cool to be able to look at all of these parameters, sensors, and controls in real time. Makes it easy to troubleshoot and make sure everything is functioning correctly.

 

[Pedestrian]

Nice progress Dave, keep it coming. This conversion is in my future and I'd rather not have to convert to obd1

 

[Viperwolf1]

Dave,
After you get this installed are you planning to smog it based the year of the engine or do you already have the collector vehicle plates?

 

[76Broncofromhell]

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.

 

[Dave]

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...

 

[RnrdTheFox]

Dave,
After you get this installed are you planning to smog it based the year of the engine or do you already have the collector vehicle plates?

They smog test mine every year as a '71 even though they see a late model 97 under the hood and I don't have collector plates... They only care whats on the vin and registration.

 

[Dave]

Connectors

Here is a photo of what I like about the OBD II system.

The harnes you see comes from the engine and splits into a Y. The PCM plugs directly into the engine harness on the left. The right side of the Y is the connector that connects the everything to the vehicle. The stock harness splits after that connector with one bundle going to the battery junction and the other to the vehicle. There are also several wires that go from the battery junction box to the vehicle. Most of those wires are unused or available for fused circuits. There is another connector visible that connects to the starter solinoid, A/C clutch, and oil level sensor. I beleive this was dont to isloate some high current circuits that could induce noise into the control and sensor lines in the PMC lines. Other than that, The battery and alternator connect to the battery junction box which provedes fused protection and relays.

I cranked it up this morning and ran the transmission through the gears. The harness provides the neutral/park lockout for the starter. When I put it in gear the engine idle was automatically bumped and it shifted smoothly up through OD. Reverse worked also. I hooked up a light via Hot in run to the alternator circuit and its charging at 14.3 volts. Things are comming together. I'm starting to clean up the harness and document.

 

[lars]

Looking better all the time, Dave. Before you spend too much time on the exhaust system, install the engine in the frame. The Bronco's frame rails are pretty close together. Since you are running the Explorer automatic you obviously won't have clutch linkage issues, but the passenger side frame rail can be intrusive.

In defense of OBD I, for those of us running a manual transmission and in particular if willing to mess with the PCM using a Tweecer, the old EEC-IV can serve quite well. The only additional smog gizmo on the older engines is the air pump, which, while it can be left off without issue, is a relative mechanical PITA if one chooses to run it (most don't). On the other hand, my setup, being EEC-IV EDIS, is totally custom and unquestionably a lot more work, particularly from a wiring standpoint (photo of totally custom harness attached).

Any thoughts on using the EEC-V Explorer stuff with a manual transmission?

 

[Dave]

I would probably go with OBD I with a manual. I'm very happy with the 94 Mustang system in front of the ZF on my first project. It is running the complete emmissions package including an air injected cat. Very nice running setup.

I paid less money for the whole 2000 Explorer engine/tranny/computer than I would have to pay for a just shift computer and putting a bunch of old parts on a low milage engine that runs like new.

I went with the stock exhaust system because I believe that the distance to the front cats and O2 sensors is important for the computer to function properly. This might be BS but its my understanding that the PMC looks at individual exhaust pulses and knows what cylinder they came from. Moving the front O2 bungs could interfere with that timing. The rear O2 sensors are just monitoring the performance of the cats so I don't think their position is as critical.

The stock exhaust system will take some modification. I need to tuck the front passenger side cat in just a little closer. The drivers side cat clears everything but hangs down farther than I like. A little tweeking and it should sit up with acceptable ground clearence. The rear cats will have to be relocated. Maybe stacked vertically instead of side by side or moved slightly and closser to the drive shaft. As soon as I resolve the VSS signal I'll be ready to drop the engine in the frame ans start fitting things up. I'm got 2 weeks off at the end of the month and hope to make major progress.

Todays task is the VSS. Might require a little engineerin to convert from the VSS variable reluctance output to the digital pulse that the OBD II PMC is reading from the ABS.

The following is a clip from the book on what the VSS is used for: The Vehicle Speed Sensor (VSS) is a variable reluctance or Hall-effect sensor that generates a waveform with a frequency that is proportional to the speed of the vehicle. If the vehicle is moving at a relatively low velocity, the sensor produces a signal with a low frequency. As the vehicle velocity increases, the sensor generates a signal with a higher frequency. The PCM uses the frequency signal generated by the VSS (and other inputs) to control such parameters as fuel injection, ignition control, transmission transaxle shift scheduling and torque converter clutch scheduling.

 

[Broncobowsher]

I would probably go with OBD I with a manual. I'm very happy with the 94 Mustang system in front of the ZF on my first project. It is running the complete emmissions package including an air injected cat. Very nice running setup.

I paid less money for the whole 2000 Explorer engine/tranny/computer than I would have to pay for a just shift computer and putting a bunch of old parts on a low milage engine that runs like new.

The exhaust system will take some modification.

Todays task is the VSS. Might require a little engineerin to convert from the VSS variable reluctance output to the digital pulse that the OBD II pcm is reading from the ABS.

First thought to that is use an octocoupler (optical coupling) On the positive side of the waveform it turns on, negative it goes off. Limiting curcuits to keep from overloading the driver as needed.