A Few Swap Wiring Questions

[eulogious]

Howdy all,

 

So I am helping Scott in Bellingham with the wiring on an EJ 2.2 swap that is going into a 1986 carbed GL(?) coupe (don't know the year of the motor), and I have a couple of questions that I couldn't find the answers for. I think I answered them, but if any of the guru's could double check me, I would greatly appreciate it

 

So here it goes!, keep in mind I am only dealing with the wiring, so assume everything else has been done correctly I am just worrying about powering it correctly for now. I guess I should also say that I did NOT cut this harness down, I am just working with what I have and this harness will need alot of TLC, but that's a different issue. I am also 200 miles away from the car as well.

 

I made this diagram to show how I want to wire up the harness:

 

 

So my first question is, do I really need to use the EJ fuel pump relay, or can I use the EA one that's already in there? If I can use the EA one that's there, where is it located? Under the dash, on the left side of the steering wheel? I don't have a FSM that has any carbed anything in it, so I could not verify.

 

What I want to do is run the ground from the ECU to the fuel pump relay ground, so it acts just like stock. So my next question that follows the same lines is, is the wire mentioned in my diagram the correct wire to tap into? The ground for the relay was the only wire that didn't change color for MPFI to SPFI, so I am hoping it didn't change from carb to fi, but please correct me on that if I am wrong

 

Since I don't have a FSM for a carb car, just my 1988 FSM which only had FI, can someone verify my wires for everything else? I am not really concerned about the colors, but more of the pins/location, but if the colors are the same, it would be sweet to know that.

 

I guess the last question, does my diagram look ok? Am I missing something?

 

This is my first time playing with a EJ swap harness, so I very well could be missing something, and any tips/tricks would be greatly appreciated!

 

Thanks all!

[Numbchux]

I believe the power going to the stock fuel pump relay is switched via the old engine control (I forget how it works....but it's designed not to have power if the engine isn't running).

 

so stock fuel relay will require 3 splices. EJ one requires 1. IMHO it's just simpler to use the EJ one. it's all wired in there like it should be, just grab that power wire and get it to the pump. done.

 

 

as for the rest. here's the page I send along with a cut harness:

http://www.numbchuxconversions.com/Files/Harness%20info.pdf

[eulogious]

I believe the power going to the stock fuel pump relay is switched via the old engine control (I forget how it works....but it's designed not to have power if the engine isn't running).

 

so stock fuel relay will require 3 splices. EJ one requires 1. IMHO it's just simpler to use the EJ one. it's all wired in there like it should be, just grab that power wire and get it to the pump. done.

 

 

as for the rest. here's the page I send along with a cut harness:

http://www.numbchuxconversions.com/Files/Harness%20info.pdf

 

Sweet, thanks for explaining why I want to use the EJ fuel pump relay. I was really curious about that one, thanks.

 

Also thanks again for the quick write up. That explains pretty much what I was gathering, but in more detail. I will have to make sure I have that guy on hand when I go up there next. Thanks again man!

 

Anyone else confirm my other questions since I don't have a fsm?

[GeneralDisorder]

Use the EJ's FP Relay - when the harness is stripped that should pretty much be left alone. Just the power wire to the pump has to be run back to the pump.

 

For the temp and oil pressure on a carbed car - I reccomend using the car's existing wireing for that. The oil pressure has to be run from a hose or tube and run to the fenderwall, etc as the EJ's don't have oil pressure - only idiot lamps. The coolant temp will not be correct unless you switch over to the EA sending unit - which takes TIG welding and rethreading the coolant cross-over for it to fit properly.

 

The start signal wire doesn't exist on the carbed harness. You have to add the pin to the harness connector for the ignition switch but the switch does support the start signal.

 

GD

[Numbchux]

The start signal wire doesn't exist on the carbed harness. You have to add the pin to the harness connector for the ignition switch but the switch does support the start signal.

 

GD

 

Sure it does. The starter gets power, doesn't it? just grab that. That's how it's done stock anyway....

[eulogious]

Use the EJ's FP Relay - when the harness is stripped that should pretty much be left alone. Just the power wire to the pump has to be run back to the pump.

 

Ok, so I updated my diagram to reflect using the EJ fuel pump relay. So instead of running a new wire to the fuel pump, I should just be able to cut the wire going to the fuel pump relay that goes to the fuel pump and tie into it that way, correct? This would avoid me having to run another wire for that… What's the color for the wire on the carbed models that goes to the fuel pump, and/or does my diagram show the location of the wire properly?

 

 

For the temp and oil pressure on a carbed car - I reccomend using the car's existing wireing for that. The oil pressure has to be run from a hose or tube and run to the fenderwall, etc as the EJ's don't have oil pressure - only idiot lamps. The coolant temp will not be correct unless you switch over to the EA sending unit - which takes TIG welding and rethreading the coolant cross-over for it to fit properly.

 

The EJ is just a dummy light correct? So I could hook the gauge up, but it will just peg itself if there is something wrong, correct?

 

As for the temp, all it does is give a reading for the driver so there isn't a need for a temp input for the ecu, correct? The CTS should be on the motor itself and should be ok without touching it. I believe this is the case, so then I should just be able to wire in a resistor and that should work in theory, so I will try that before switching anything over…

 

The start signal wire doesn't exist on the carbed harness. You have to add the pin to the harness connector for the ignition switch but the switch does support the start signal.

 

Sure it does. The starter gets power, doesn't it? just grab that. That's how it's done stock anyway....

 

I plan on tapping into the starter wire in the ignition for the "choke" on the ecu, since that wire only gets power when starting, so it should work fine, correct?

 

Here are some diagrams of the ECU I/O that I took the liberty of highlighting what seems to be the important wires. The yellow highlight is what is required for me to tap into for the engine to run (the temp sensor highlight is wrong, but I didn't want to reupload the photo, so ignore it ), the red highlight are the grounds, and the blue highlight is what I am not sure about. They are not the same diagrams that Chux has, but they are from a 1992 Legacy MPFI non-turbo, so the wire locations should be the same, just different connector names/numbering… These diagrams are a little clearer as well, but correct me if these diagrams are wrong.

 

 

How critical are the shields? What about the neutral switch and the ignition switch, are they needed for the motor to run correctly? Do I have everything that is important highlighted that I need to tap into? I am going to use this to double check the harness as well to make sure I have good connections where I need them, and having it highlighted properly would make it lots easier

 

Sorry for all the questions, I just want to make sure I am doing this correctly, and I am trying to avoid any major mistakes on my part since I have never done this before So thanks for all the help so far guys!

Edited September 3, 2010 by eulogious

[Gloyale]

You can't really use the EA "relay" as it's not the same setup. It has what fuji called the "rev Sensor" also called the FPCU (fuel pump control unit) It's a black box, half the size of a card deck. Mounted to the bracket with the hood release pull. (drivers side kickpanel) usually has a Mitsu style 3 diamond logo on it.

 

Basically it passes power to the Fuel pump, as well as the anti-diesel solenoid only when ignition pulse is present.

 

The connector that plugs into that box has 6 wirestotal, 3 or 4wires you can use.

 

- Blue/red wire is the fuel pump power wire. You can run power out of the EJ FP relay to this connector, so you don't have to run a wire back to pump.

 

-Yellow is the EA tach wire.....run your EJ tach signal to that wire and it will feed to the tachometer in dash.

 

-And if you want...it's a good place to get switched power for signaling the EJ main relay

 

-There is also a ground wire in that connector so you could actually use that too.

 

 

IMO, that the wiring for Carbed models is entirely different. You should disregard that 88 FSM....it won't really help.

 

But here's this

Edited September 3, 2010 by Gloyale

[eulogious]

You can't really use the EA "relay" as it's not the same setup. It has what fuji called the "rev Sensor" also called the FPCU (fuel pump control unit) It's a black box, half the size of a card deck. Mounted to the bracket with the hood release pull. (drivers side kickpanel) usually has a Mitsu style 3 diamond logo on it.

 

Basically it passes power to the Fuel pump, as well as the anti-diesel solenoid only when ignition pulse is present.

 

The connector that plugs into that box has 6 wirestotal, 3 or 4wires you can use.

 

- Blue/red wire is the fuel pump power wire. You can run power out of the EJ FP relay to this connector, so you don't have to run a wire back to pump.

 

-Yellow is the EA tach wire.....run your EJ tach signal to that wire and it will feed to the tachometer in dash.

 

-And if you want...it's a good place to get switched power for signaling the EJ main relay

 

-There is also a ground wire in that connector so you could actually use that too.

 

 

IMO, that the wiring for Carbed models is entirely different. You should disregard that 88 FSM....it won't really help.

 

But here's this

 

Ahh, I get it. They needed some way to be able to control the fuel pump when the engine is running, and since they didn't have a computer running everything, they needed a way to sense when the engine is running, so they came up with that guy. This was then replaced by the relay when the computer was brought into the equation. Thanks for the explanation on the carbed fuel pump "relay", it all makes sense now

 

Thanks for the diagram as well! Is there anyway I can get a more high res pic from you on that? It would be handy to see it all and be able to read it clearly, and I might be able to answer some of my own questions. But it's better than nothing Thanks for the wire break down as well, that will help tremendously

 

I was sitting here thinking about where would be the smartest place to tap into some of these wires, and I realized that some of them are already in the engine bay so I should just tap into them instead of using the ones in the dash. Duh! But the problem is I don't know what wires are what in the engine bay since I did not pull the motor, nor do I have any diagrams of these wires. The only wires that I need to know that I think would be in the engine compartment already would be the oil pressure wire and the temp gauge wire. Those would have to be in the engine compartment.

 

So does anyone with a '86 FSM know where I can find these 2 wires in the engine bay?

 

And the neutral switch, how does it get "hooked up"? Is it just grounded? Looks like it is…

 

 

 

Ok, so here's the breakdown of what I plan on doing to get it all wired in, so correct me if something doesn't seem right I am just trying to get my ducks in a row.

 

1. Get the fuel pump power from the EJ fuel pump relay using the blue/red wire (goes directly to fuel pump) off the FPCU.

 

2. Wire in the tach signal from the EJ ECU to the tach wire coming from the FPCU.

 

3. Wire in a ~270ohm resistor on the temp gauge wire in the engine compartment, and wire that in to the existing wire in the engine bay.

 

4. Wire in the "dummy" light for oil pressure from the wire in the engine bay.

 

5. Get the switched power from the FPCU to power the EJ ignition relay (what color wire is it? The car doesn't have a battery as of now, and I don't want to put one in just to find this wire, so any help would be great ).

 

6. Get the VSS signal from the back of the dash off the reed switch in the speedo (wire color would be sweet ).

 

7. Get the check engine light from the dash connector. i-38, should be the light green wire in the upper right when looking down at the connector.

 

8. Get the "choke" wire from the starter wire (black, fused) in the ignition switch.

 

9. Run a wire directly off the battery (fused) to power the ECU always.

 

10. Wire in the radiator fans either off their own switch/relay, or by letting the ECU control them.

 

11. Ground(?) the neutral switch to prevent the CEL from coming on for no reason.

 

 

 

I think that about does it for all the connections I need to tap into for this all to work, correct?

 

Again, thanks for all the help so far!

[Numbchux]

Ahh, I get it. They needed some way to be able to control the fuel pump when the engine is running, and since they didn't have a computer running everything, they needed a way to sense when the engine is running, so they came up with that guy. This was then replaced by the relay when the computer was brought into the equation. Thanks for the explanation on the carbed fuel pump "relay", it all makes sense now

 

Thanks for the diagram as well! Is there anyway I can get a more high res pic from you on that? It would be handy to see it all and be able to read it clearly, and I might be able to answer some of my own questions. But it's better than nothing Thanks for the wire break down as well, that will help tremendously

 

I was sitting here thinking about where would be the smartest place to tap into some of these wires, and I realized that some of them are already in the engine bay so I should just tap into them instead of using the ones in the dash. Duh! But the problem is I don't know what wires are what in the engine bay since I did not pull the motor, nor do I have any diagrams of these wires. The only wires that I need to know that I think would be in the engine compartment already would be the oil pressure wire and the temp gauge wire. Those would have to be in the engine compartment.

 

So does anyone with a '86 FSM know where I can find these 2 wires in the engine bay?

 

And the neutral switch, how does it get "hooked up"? Is it just grounded? Looks like it is…

 

 

 

Ok, so here's the breakdown of what I plan on doing to get it all wired in, so correct me if something doesn't seem right I am just trying to get my ducks in a row.

 

1. Get the fuel pump power from the EJ fuel pump relay using the blue/red wire (goes directly to fuel pump) off the FPCU.

 

2. Wire in the tach signal from the EJ ECU to the tach wire coming from the FPCU.

 

3. Wire in a ~270ohm resistor on the temp gauge wire in the engine compartment, and wire that in to the existing wire in the engine bay.

 

4. Wire in the "dummy" light for oil pressure from the wire in the engine bay.

 

5. Get the switched power from the FPCU to power the EJ ignition relay (what color wire is it? The car doesn't have a battery as of now, and I don't want to put one in just to find this wire, so any help would be great ).

 

6. Get the VSS signal from the back of the dash off the reed switch in the speedo (wire color would be sweet ).

 

7. Get the check engine light from the dash connector. i-38, should be the light green wire in the upper right when looking down at the connector.

 

8. Get the "choke" wire from the starter wire (black, fused) in the ignition switch.

 

9. Run a wire directly off the battery (fused) to power the ECU always.

 

10. Wire in the radiator fans either off their own switch/relay, or by letting the ECU control them.

 

11. Ground(?) the neutral switch to prevent the CEL from coming on for no reason.

 

 

 

I think that about does it for all the connections I need to tap into for this all to work, correct?

 

Again, thanks for all the help so far!

 

 

Alright, first off. where did you get that pinout? it's strange, as it looks like the FSM one, but shares none of the plug references (B125, B126, etc.) with any '92 legacy diagram I've seen. also the pinouts I've had have turbo and non-turbo listed, as there are only a handful of wires that are different.

 

 

anyway, all those wires for the sensors. just leave em alone. the shielded wires for the CASs are only hooked up to the ECU and sensor plugs. so you shouldn't have to touch them. They should remain shielded to ensure a good signal, but if need be, it's not entirely necessary. I ran 2 seperate wires for the crank sensor on my loyale EJ22 swap when the shielded wire became damaged.

 

 

 

almost all of those wires can be found either at the ignition switch or the back of the gauge cluster. that is, by far, the easiest way to track everything down. beats the heck out of tracking them down individually in the engine bay.

 

all EA82s have an oil light in the strip of idiot lights below the gauges. IMHO, just wire it to that, and be done with it.

 

ignition switch is what turns the ECU on. so yes, you need that.

 

neutral switch needs to be hooked up to a neutral or clutch switch to not throw a code. always disconnected or always grounded will be equally faulty. some carbed EA82s have a clutch pedal switch, otherwise, they're easy to install. just get the switch and plug from a car with one, and replace the stopper bolt on the pedal box.

[GeneralDisorder]

neutral switch needs to be hooked up to a neutral or clutch switch to not throw a code. always disconnected or always grounded will be equally faulty. some carbed EA82s have a clutch pedal switch, otherwise, they're easy to install. just get the switch and plug from a car with one, and replace the stopper bolt on the pedal box.

 

SPFI Loyale's have the clutch switch as well for the newer SPFI computer's that wanted both clutch and neutral.

 

GD

[eulogious]

Alright, first off. where did you get that pinout? it's strange, as it looks like the FSM one, but shares none of the plug references (B125, B126, etc.) with any '92 legacy diagram I've seen. also the pinouts I've had have turbo and non-turbo listed, as there are only a handful of wires that are different.

 

I got it from the pirat3bay Torrents are wonderful things It's a 1992 FSM complete scan in one pdf. It's about 55mb and book marked really nicely as well. When I compared the two pinouts (mine and yours) they all seemed the same for the non-turbo. And this scan was easier to read because it didn't have the turbo info on it, and it was a better scan. But if it is different let me know, but it didn't look like it.

 

 

anyway, all those wires for the sensors. just leave em alone. the shielded wires for the CASs are only hooked up to the ECU and sensor plugs. so you shouldn't have to touch them. They should remain shielded to ensure a good signal, but if need be, it's not entirely necessary. I ran 2 seperate wires for the crank sensor on my loyale EJ22 swap when the shielded wire became damaged.

 

I wasn't going to touch them, I am just going to double check them to make sure they are still good. Remember I didn't cut this harness down, so I know have to go through it to make sure it's all correct. I just wanted to verify that those are all the wires that I need to double check to make this thing run.

 

Thanks for the info on the shield. I didn't think it was required (the only reason it's shielded is because it's a sine wave signal, like an audio signal, so it can suffer from signal attenuation over long distances). Since the ECU will be located in the engine bay, it doesn't have very far to travel. But I will double check them.

 

almost all of those wires can be found either at the ignition switch or the back of the gauge cluster. that is, by far, the easiest way to track everything down. beats the heck out of tracking them down individually in the engine bay.

 

all EA82s have an oil light in the strip of idiot lights below the gauges. IMHO, just wire it to that, and be done with it.

 

ignition switch is what turns the ECU on. so yes, you need that.

 

neutral switch needs to be hooked up to a neutral or clutch switch to not throw a code. always disconnected or always grounded will be equally faulty. some carbed EA82s have a clutch pedal switch, otherwise, they're easy to install. just get the switch and plug from a car with one, and replace the stopper bolt on the pedal box.

 

Cool, thanks for letting me know the easiest way to get the wires is in the dash. I will go that route.

 

Thanks for the tip about the oil light, I will find that and use that, it's perfect!

 

Good to know that is what is meant by ignition, I will make sure that guy is hooked up.

 

And the neutral switch should be easy to do as well, so I will just do it once and do it correctly.

 

Thanks for all the help everyone! If it all looks good, then hopefully I can get this thing wired up and running pretty easily! If anyone has any other tips/tricks for the wiring part of this, feel free to chime in!