Engine Swap Leessons Learned, Do's, Don'ts & Wished I Would Haves

[Gary Lewis]

The EEC has nothing to do with firing order - it doesn't control the ignition system directly. And the injectors are bank-fired, so the firing order still doesn't matter. The difference in distance between the injector banks is smaller than the slack in the harness, so it'll fit either engine. No downstream HEGO until '96, so even though deleting the cats is a bad idea, the EEC wouldn't know about it.

Good points, Steve.

As for deleting the cats, unless they are plugged they don't hurt performance, and they help the environment. But, if you delete the AIR system then the cats probably won't work correctly. And the ECU may detect the absence of the AIR system if you remove it completely. I'm not sure what can be removed w/o the ECU detecting it.

Steve?

[Steve Mikkelson]

Good points, Steve.

As for deleting the cats, unless they are plugged they don't hurt performance, and they help the environment. But, if you delete the AIR system then the cats probably won't work correctly. And the ECU may detect the absence of the AIR system if you remove it completely. I'm not sure what can be removed w/o the ECU detecting it.

Steve?

Thank you for sharing your knowledge guys. I appreciate the willingness to collaborate and hope I can return some useful information when someone else needs a hand.

My '86 is a California truck that has been certified and passed their inspection three years ago so basically up to California stringent emission standards

'94 is providing the engine and it is a Michigan truck with emission controls that I believe resemble the other 48 states.

Please correct my logic if it is flawed here, but from what I am piecing together here...

If I keep the '86 wire harness & computer and then plug into the '94 engine, I suspect there will be additional issues to address on top of the cats as mentioned.

If I use the original '94 computer, wire harness with its married engine, there will likely be other unknown issues to deal with, but I suspect removing the cats would not be one of them?

As far as the wire harness length, I have suspicion about the relative length. The '86 computer is currrently mounted inside the cab under the instrument panel just above the transfer case shifter. The '94 computer is mounted in the firewall directly inline with the drivers side front tire. I kept every wireharness from the '94 because I figured my ignorance would bite me if I threw it away.

I probably should mention that every serpentine driven component from the '94 is staying with the engine when it finds its home in the '86. Would that create additional concerns?

Again group, much appreciated that you are willing to give up some of your time to transfer knowledge to a fella you don't really know. Thank you!

 

[Gary Lewis]

Thank you for sharing your knowledge guys. I appreciate the willingness to collaborate and hope I can return some useful information when someone else needs a hand.

My '86 is a California truck that has been certified and passed their inspection three years ago so basically up to California stringent emission standards

'94 is providing the engine and it is a Michigan truck with emission controls that I believe resemble the other 48 states.

Please correct my logic if it is flawed here, but from what I am piecing together here...

If I keep the '86 wire harness & computer and then plug into the '94 engine, I suspect there will be additional issues to address on top of the cats as mentioned.

If I use the original '94 computer, wire harness with its married engine, there will likely be other unknown issues to deal with, but I suspect removing the cats would not be one of them?

As far as the wire harness length, I have suspicion about the relative length. The '86 computer is currrently mounted inside the cab under the instrument panel just above the transfer case shifter. The '94 computer is mounted in the firewall directly inline with the drivers side front tire. I kept every wireharness from the '94 because I figured my ignorance would bite me if I threw it away.

I probably should mention that every serpentine driven component from the '94 is staying with the engine when it finds its home in the '86. Would that create additional concerns?

Again group, much appreciated that you are willing to give up some of your time to transfer knowledge to a fella you don't really know. Thank you!

I think the easiest thing to do is to just put the 5.8L in place of the 5.0L and run the original wiring and ECU. As Steve said, the system is bank fire so the engine's firing order doesn't matter. And, also as he said, the ECU doesn't determine the ignition's firing order. It just figures out when to fire the ignition, not what cylinder to send it to.

But, the concern I have is the amount of fuel it will give the engine. It is geared for a 5.0L engine and is assuming it knows how much air is ingested. But the engine will be pulling in 16% more air than a 5.0L would have, so I'm wondering if the ECU will be able to properly compensate.

However, you may be able to plug the 5.8L's ECU in where the 5.0L's is and it'll be happy. But, the question that needs to be answered before you attempt that is whether Ford changed something in the wiring between the two years/systems.

Fortunately Bill Vose/85lebaront2 has done quite a bit of work that should help in answering that question. He's compiled in spreadsheet form the pinout of many of the different systems, and I have it on the website here: http://www.garysgaragemahal.com/efi.html. But it is going to take some work to compare pinouts. You need to go to the Pinout tab, then go to the 5.0L tab at the bottom and compare the circuit numbers for each pin with the same pin on the 5.8L tab for 1994.

It is a tedious process, but I would want to do it before I attempted to plug the '94 computer into the '86 harness.

And, speaking of harness, given the difference in mounting locations for the ECU, you are really stuck with the '86 harness. That's because your body style doesn't have the mod's that allow the ECU to be mounted where it is on the '94.

And the serpentine system shouldn't cause any problems.

[NotEnoughTrucks]

Thank you for sharing your knowledge guys. I appreciate the willingness to collaborate and hope I can return some useful information when someone else needs a hand.

My '86 is a California truck that has been certified and passed their inspection three years ago so basically up to California stringent emission standards

'94 is providing the engine and it is a Michigan truck with emission controls that I believe resemble the other 48 states.

Please correct my logic if it is flawed here, but from what I am piecing together here...

If I keep the '86 wire harness & computer and then plug into the '94 engine, I suspect there will be additional issues to address on top of the cats as mentioned.

If I use the original '94 computer, wire harness with its married engine, there will likely be other unknown issues to deal with, but I suspect removing the cats would not be one of them?

As far as the wire harness length, I have suspicion about the relative length. The '86 computer is currrently mounted inside the cab under the instrument panel just above the transfer case shifter. The '94 computer is mounted in the firewall directly inline with the drivers side front tire. I kept every wireharness from the '94 because I figured my ignorance would bite me if I threw it away.

I probably should mention that every serpentine driven component from the '94 is staying with the engine when it finds its home in the '86. Would that create additional concerns?

Again group, much appreciated that you are willing to give up some of your time to transfer knowledge to a fella you don't really know. Thank you!

Couple of things you may want to consider.

The later model ECM may also have transmission controls, likely for an E4OD. If you use a non electronically controlled transmission, like an AOD or a C6, the ECM will not be very happy.

There are a few small changes between the 86 ECM's and the later EECIV ECM's. I did a spreadsheet some time ago, perhaps this will help?

Year_comparisons_SD_compatibility.pdf

[Gary Lewis]

Couple of things you may want to consider.

The later model ECM may also have transmission controls, likely for an E4OD. If you use a non electronically controlled transmission, like an AOD or a C6, the ECM will not be very happy.

There are a few small changes between the 86 ECM's and the later EECIV ECM's. I did a spreadsheet some time ago, perhaps this will help?

Year_comparisons_SD_compatibility.pdf

Excellent points, Ray.

[85lebaront2]

I think the easiest thing to do is to just put the 5.8L in place of the 5.0L and run the original wiring and ECU. As Steve said, the system is bank fire so the engine's firing order doesn't matter. And, also as he said, the ECU doesn't determine the ignition's firing order. It just figures out when to fire the ignition, not what cylinder to send it to.

But, the concern I have is the amount of fuel it will give the engine. It is geared for a 5.0L engine and is assuming it knows how much air is ingested. But the engine will be pulling in 16% more air than a 5.0L would have, so I'm wondering if the ECU will be able to properly compensate.

However, you may be able to plug the 5.8L's ECU in where the 5.0L's is and it'll be happy. But, the question that needs to be answered before you attempt that is whether Ford changed something in the wiring between the two years/systems.

Fortunately Bill Vose/85lebaront2 has done quite a bit of work that should help in answering that question. He's compiled in spreadsheet form the pinout of many of the different systems, and I have it on the website here: http://www.garysgaragemahal.com/efi.html. But it is going to take some work to compare pinouts. You need to go to the Pinout tab, then go to the 5.0L tab at the bottom and compare the circuit numbers for each pin with the same pin on the 5.8L tab for 1994.

It is a tedious process, but I would want to do it before I attempted to plug the '94 computer into the '86 harness.

And, speaking of harness, given the difference in mounting locations for the ECU, you are really stuck with the '86 harness. That's because your body style doesn't have the mod's that allow the ECU to be mounted where it is on the '94.

And the serpentine system shouldn't cause any problems.

One item you will see right off, the 1985.5 and 1986 EECs did not use a speed sensor, the other is the relocation of some power and ground pins and the final is the change in EGR valve control in 1987 from the dual valves (vacuum and vent) to a "dithering" single valve that combines both vacuum and vent in one valve.

[Steve Mikkelson]

Thanks fellas! I appreciate the guidance. Makes me think the simplicity of a carburetor may start to challenge benefits the provides EFI.

It is helping me to realize where my line of ignorance begins and where I need to gain more knowledge to tackle this project. I enjoy learning new stuff, but when it goes outside of my core compotnecies, it takes a bit longer for this guy to catch on. Like the old saying goes, "you don't know what you don't know." Keep it coming please.

[Steve83]

I'm not sure what can be removed w/o the ECU detecting it.

I prefer to look at it from a different perspective: how many things can I keep working the way the engineers engineered them to work?

This is an article I wrote about emissions systems.

If I keep the '86 wire harness & computer and then plug into the '94 engine...

I'm not sure where exactly you're talking about plugging in, so I'm not sure what you're imagining is even possible. Many connectors changed shape between those years.

If I use the original '94 computer, wire harness with its married engine, there will likely be other unknown issues to deal with...?

I think that will result in the FEWEST issues to deal with. That's how I've always done engine swaps, and all mine have been very reliable & maintainable.

The '86 computer is currrently mounted inside the cab under the instrument panel just above the transfer case shifter.

That was one of several early EEC locations.

The '94 computer is mounted in the firewall directly inline with the drivers side front tire.

That's the standard '87-96 location.

Would that create additional concerns?

Again: I think it will minimize your problems; both during the swap, and in the years of driving to come.

...I'm wondering if the ECU will be able to properly compensate.

I've never run the wrong EEC, but I've heard from many people who have that they run OK. The EEC will default to its (now-incorrect) baseline the first time he powers it up, but it will learn & adapt as the engine runs, and always try to achieve stoicheometry based on the HEGO.

http://supermotors.net/getfile/507315/thumbnail/hegoloc.jpg

...compare the circuit numbers for each pin with the same pin on the 5.8L tab for 1994.

I made this diagram, but it's actually based on '87-96 trucks:

http://supermotors.net/getfile/892730/thumbnail/eecconnectors.jpg

It may NOT be correct for older EFIs.

That's because your body style doesn't have the mod's that allow the ECU to be mounted where it is on the '94.

I found that was pretty easy to fix when I put the '95 engine, EEC, & wiring into my '83's '82 body tub:

http://supermotors.net/getfile/65187/thumbnail/body_lf.jpg

http://supermotors.net/getfile/71679/thumbnail/eec-install.jpg

If you use a non electronically controlled transmission, like an AOD or a C6, the ECM will not be very happy.

Many people think that, but I helped a local friend switch his '94 Bronco from E4OD to stick, and he didn't want to buy another EEC, so he just drove it. We found that, although the EEC does set DTCs for the missing trans, those don't turn on the CEL, and it has no effect on how the EEC manages the engine. So it ran fine for many years. Eventually, he sold it to his brother (still running fine), so IDK what its current status is.

Makes me think the simplicity of a carburetor may start to challenge benefits the provides EFI.

Not even close. EFI is the way it always should have been done. Carbs suck.

[Gary Lewis]

I'm not sure what can be removed w/o the ECU detecting it.

I prefer to look at it from a different perspective: how many things can I keep working the way the engineers engineered them to work?

This is an article I wrote about emissions systems.

If I keep the '86 wire harness & computer and then plug into the '94 engine...

I'm not sure where exactly you're talking about plugging in, so I'm not sure what you're imagining is even possible. Many connectors changed shape between those years.

If I use the original '94 computer, wire harness with its married engine, there will likely be other unknown issues to deal with...?

I think that will result in the FEWEST issues to deal with. That's how I've always done engine swaps, and all mine have been very reliable & maintainable.

The '86 computer is currrently mounted inside the cab under the instrument panel just above the transfer case shifter.

That was one of several early EEC locations.

The '94 computer is mounted in the firewall directly inline with the drivers side front tire.

That's the standard '87-96 location.

Would that create additional concerns?

Again: I think it will minimize your problems; both during the swap, and in the years of driving to come.

...I'm wondering if the ECU will be able to properly compensate.

I've never run the wrong EEC, but I've heard from many people who have that they run OK. The EEC will default to its (now-incorrect) baseline the first time he powers it up, but it will learn & adapt as the engine runs, and always try to achieve stoicheometry based on the HEGO.

http://supermotors.net/getfile/507315/thumbnail/hegoloc.jpg

...compare the circuit numbers for each pin with the same pin on the 5.8L tab for 1994.

I made this diagram, but it's actually based on '87-96 trucks:

http://supermotors.net/getfile/892730/thumbnail/eecconnectors.jpg

It may NOT be correct for older EFIs.

That's because your body style doesn't have the mod's that allow the ECU to be mounted where it is on the '94.

I found that was pretty easy to fix when I put the '95 engine, EEC, & wiring into my '83's '82 body tub:

http://supermotors.net/getfile/65187/thumbnail/body_lf.jpg

http://supermotors.net/getfile/71679/thumbnail/eec-install.jpg

If you use a non electronically controlled transmission, like an AOD or a C6, the ECM will not be very happy.

Many people think that, but I helped a local friend switch his '94 Bronco from E4OD to stick, and he didn't want to buy another EEC, so he just drove it. We found that, although the EEC does set DTCs for the missing trans, those don't turn on the CEL, and it has no effect on how the EEC manages the engine. So it ran fine for many years. Eventually, he sold it to his brother (still running fine), so IDK what its current status is.

Makes me think the simplicity of a carburetor may start to challenge benefits the provides EFI.

Not even close. EFI is the way it always should have been done. Carbs suck.

Steve83 - Please tell us more about how you put the ECA in the kick panel on your '82. I'm going with EEC-V on Dad's '81 and have been thinking through where to put the ECA in it. So I'm interested in how you did it as it may well be the way to do it for mine.

It brings up questions like:

• Was the '95 EEC-IV or V?

• Did you have to dimple or cut into the kick panel?

• Were you able to put the plastic trim panel on?

• Did you have to lengthen the later wiring?

[Steve83]

...tell us more about how you put the ECA in the kick panel on your '82.

I saw that's where it belonged on later trucks, so I tried to cram it in there from inside. But the e-brake was too close to the lower A-pillar/kick, so I slotted its firewall holes & slid it over. Then I cut the firewall near the A-pillar, and folded the steel back to make the size & shape hole to fit the EEC. Then I cut the bent steel flush with the firewall & slathered it with fiberglass (or Bondo - whatever) to seal it, and to give the EEC seal something to seal against. Hose it down with paint, and stick the EEC in.

Was the '95 EEC-IV or V?

EEC-V (OBD-II) started in '96 for these trucks.

http://supermotors.net/getfile/731920/thumbnail/eec95way1.jpg

Did you have to dimple or cut into the kick panel?

Not the steel A-pillar/kick, but I cut the plastic kick trim.

http://supermotors.net/getfile/71661/thumbnail/pcm-inside-text.jpg

Did you have to lengthen the later wiring

No, the truck is the same size, and I put the EEC where it was supposed to be, so the wiring fit fine.