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EA82T MPFI to EA82 SPFI swap.... not plug and play


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15 replies to this topic

#1 4RnrRick

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Posted 09 November 2006 - 04:14 PM

I need some help here!

I've acquired (4) subies in different conditions to try to make two good cars to maybe keep or resell. (probably resell)

Car 1.) 07/88 Wagon, EA82 SPFI, D/R 4wd 5 speed - Tree fell on it so the roof is trashed but the motor is good.
Car 2.) 01/88 Wagon, EA82T MPFI, PB 4wd 5 speed - Minor frent end damage (already repaired) but the motor has a knock.


Car 3.) 01/89 Wagon, EA82 SPFI, D/R 4wd 5 speed - Rear ended so the body is trashed but the motor is good.
Car 4.) 10/89 Wagon, EA82T MPFI, Auto 4 speed - nice body but the motor has a hole in the block.

I bought them from "ddog87" which is a 4 wheel'n buddy of mine. His post about the cars when he had them is here.
http://www.ultimates...ead.php?t=66717

And I started a post about Cars 3 & 4 here since I was concerned about the auto to manual wiring harnesses:
http://www.ultimates...ead.php?t=66887

Anyhoo, I figured I would start with the first two manual transmission cars {EA82 SPFI, D/R 4wd 5 speed} & {EA82T MPFI, PB 4wd 5 speed} since they should be the easier ones to swap. So I pulled both motors, wiring harness and ECM's. Last night I got the EA82 SPFI motor, harness, ECM installed into the Turbo P/B 4wd Wagon. I compared the harness before I installed it and there were some major differences (one large plug under the dash, the 4wd Push Button solenoids and one tranny plug) So I swapped over the 4wd Push Button solenoid plug and I installed it hoping it would work - knowing that I probably only had about a 5% chance of it actually working. but I had to try since I had everythign torn apart that far. Well I it cranks over but thats it. I have no spark, no fuel pressure and no power to the ECM. Basically I've determined that its NOT plug and play even with swapping of the wiring harness back to the ECM.

So where do I go from here? Looks like I have a few options.

A) Try to hardwire power to the ECM and see if I have spark then? How would I do that? my book shows a Red/Blu is the power to the computer but there are several wires with that color in the harness. Does anyone have a labeled Schematic for the ECU plug wires?

B) Swap over dash harness and see what happens - which might eventually mean I will also have to swap Trannys, CV, driveline and rear diff.

C) Swap the MPFI harness back into car and make a high compression SPFI motor (remove turbo stuff) using MPFI heads?

D) Give up and burn them to the ground...

#2 4RnrRick

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Posted 09 November 2006 - 04:28 PM

http://www.ultimates...=1&d=1163107584

http://www.ultimates...=1&d=1163107584

http://www.ultimates...=1&d=1163107584

http://www.ultimates...=1&d=1163107584

http://www.ultimates...=1&d=1163107584

Attached Files



#3 GeneralDisorder

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Posted 09 November 2006 - 05:33 PM

I can definately help you with the SPFI wireing, but this is going to take some work, and I might need to talk you through it over the phone or something...

You have two options I guess:

1) try and make the SPFI harness work without taking it apart. I don't have a complete harness for reference just at the moment, but I'm pretty sure your problems are associated with the dash harness pin-outs - the fuel pump relay supplies power to the fuel pump through the dash harness, and at least one of the ECU power circuits (there's 3) goes through the dash harness as well....

2) strip out the ECU, power, and sensor portion of the harness and piggyback it to the MPFI harness. Basically letting the MPFI harness handle the "car" (including your transmission, backup lights, 4WD button, and all the other myriad stuff that's going to be a huge PITA with trying to use the MPFI harness) and running the engine with the piggyback.

If it were me (and because I've done this before), I would choose #2. It's much more predictable and you are almost gauranteed that it will work. It has the side benefit of being 100% reversible if anyone ever wanted to put a turbo motor back in....

I'm actually working on a wite-up on exactly this sort of thing. My write up deals with specifically converting carbed engines to SPFI, but as many carbed engines were also computer controlled, it's nearly identical to what you are doing, except it will be easier for you.

Here's a picture to get you oreiented to what you need exactly from the SPFI harness (you can lose over half of it by taking out only the engine section). My complete write up isn't totally ready yet, but I will help you with whatever I can...

Posted Image

GD

#4 4RnrRick

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Posted 09 November 2006 - 05:57 PM

Now that I'm dealing with this (like you said in the other thread) I'm really not that found of the whole idea? Mostly for teh fact that I don't have any good wiring harness info.

Can I just swap the dash harness between the two cars? How big is the dash harness???? Is it the rest of the car (dash back) ??? or just under the dash?

#5 GeneralDisorder

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Posted 09 November 2006 - 06:04 PM

Now that I'm dealing with this (like you said in the other thread) I'm really not that found of the whole idea? Mostly for teh fact that I don't have any good wiring harness info.


Yeah - tell me about it. Even the FSM's are woefully inadequate for this kind of a job - they deal with how to "fix" it, not how to redesign it. :rolleyes:

Can I just swap the dash harness between the two cars? How big is the dash harness???? Is it the rest of the car (dash back) ??? or just under the dash?



In order to swap it, you will have to remove the dash - the dash harness ends on the passenger side where the "rear-end" harness starts. That's a huge nightmare too, and even then if you swap it, you won't be able to use the push-button 4WD system without wiring that up - it's not going to match up with the gauge cluster wireing, and I'm not even sure the dash harness will work with the rear-end harness..... you travel into uncharted territory if you go that route. If you piggyback the SPFI harness, it will just work, and you won't have to worry about anything other than giving it power, and hooking it into a half a dozen wires under the dash that are easily accesible.

GD

#6 4RnrRick

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Posted 09 November 2006 - 06:14 PM

Thanks for the info - I think I'm going to investigate the complexitiy of the dash harness some more...

Wiring up the PB tranny looks pretty simple from what I seen. Its just that I'm this far into it and I kinda lost on whats the best way to finish the job for me and the information I have available......

#7 Snowman

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Posted 09 November 2006 - 09:46 PM

Very nice pic of the SPFI harness, GD. I'm gonna save that one.

Not to steal any of GD's credit, as he has done a lot more work on the SPFI swap than I have, I would mention that I figured it out from scratch two years ago by looking at the FSM and my Haynes manual. I did the option GD recommened, leaving the stock harness intact and just adding the stuff to make the SPFI work. It was not that hard, and it took me about two days to do the electrical portion of the swap (I was converting a carbed car to SPFI, retaining the engine itself. Changing over all the "hardware" took another day or so).

One thing I found incredibly helpful when sorting out the wiring was to completely ignore the FSM's schematics, which are hard to read, and just look at all the individual system wiring diagrams, which are superb. It was a lot easier to figure out which wire was which that way than trying to look at the whole thing at once. Another thing to mention is that once you actually strip off all the insulation and junk, and find the major power supplies and stuff, the SPFI wiring harness if pretty self-explainatory.

Having pulled the entire dash harness and everything from the donor car, I can say that it would probably be a lot more work to do a complete harness swap than leaving the existing harness in place and "piggybacking" the SPFI harness on top of it.

Edit: I just remembered that I know a guy who did an EA82T to SPFI swap by changing the whole harness. It took him like a month to figure it out and he swears he'll never do it again.

#8 4RnrRick

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Posted 09 November 2006 - 11:28 PM

Tonight I decided to try to pull the dash harness from my donor car. I found out its really pretty simple to do. There is a couple cables (for vents), a couple vaccumm lines (for the vents), a bundle of plugs behind each kick panel (driver side and passenger side, 1 ground wire under the center console and 7 bolts and your can remove the complete dash (fully assemblied) from the car with the harness in it... Oh I also lowered the steering coloumn down by removing the bolts that hold it to the dash support bracket.

It was so easy to do that I also did it to my good car.

http://www.ultimates...92&d=1163132836

And after a bit of chasing wires down from the Push Button 4wd switch, I think I've got that figured out. on which wires I need to transfer to the new dash harness. Solid blue wire and a Green/yellow wire that goes from the main black connector on the driver side to the main white connector on the passenger side.

Anyways this is the route I'm going right now and so far it hasn't been that bad. I just work on it a couple hours a night and so far with everything I've done - I might be up to 12+/- hours, and that includes reparing the front of the good car since it was damaged slightly.

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#9 daeron

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Posted 10 November 2006 - 12:16 AM

the wiring method is really a question of thoroughness, and how willing you are to be re-engineering a vehicle based on designs and using parts built by Fuji Heavy Industries...

It would be a much easier question to simply make the SPFI harness work in the car that came originally equipped with the turbo. However, even to do that is at LEAST half the work of completely re engineering it.. and completely re engineering it offers the advantages of

A) Having a clearer picture of how everything goes together in each vehicle,

B) Having a clearer picture of what needs to be eliminated
and
C) Having a clearer idea of where certain things need to be crossed/bypassed/switched around.

Its not that much more WORK to do it "all the way," it simply requires MUCH more patience and a bit more analysis. The end result, however, is a product of your own creation, that YOU KNOW works 110%. You also know How it works, 110%. But, it does take more time, effort, and patience. It brings you knowledge, though, rather than requiring you to obtain it. This is from all that you get to SEE....

#10 GeneralDisorder

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Posted 10 November 2006 - 04:14 AM

Very nice pic of the SPFI harness, GD. I'm gonna save that one.


No need to save it - I have LOTS more. Wait till my write up goes live. If you like that one, you are going to crap yourself....

Not to steal any of GD's credit, as he has done a lot more work on the SPFI swap than I have, I would mention that I figured it out from scratch two years ago by looking at the FSM and my Haynes manual.


"If I have seen farther, it is only because I have stood on the shoulders of giants."

You'll be getting credit in my write up, as well as a prominant link to your original PDF, which is EXCELENT (I read it before doing my first conversion), but just a bit lacking in pictures I felt. That, and my version is not only dealing with the conversion, but the modifications needed to adapt to the EA81 (where pictures are even more critical).

GD

#11 daeron

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Posted 10 November 2006 - 04:38 AM

No need to save it - I have LOTS more. Wait till my write up goes live. If you like that one, you are going to crap yourself....



"If I have seen farther, it is only because I have stood on the shoulders of giants."

You'll be getting credit in my write up, as well as a prominant link to your original PDF, which is EXCELENT (I read it before doing my first conversion), but just a bit lacking in pictures I felt. That, and my version is not only dealing with the conversion, but the modifications needed to adapt to the EA81 (where pictures are even more critical).

GD



I second all his statements. Good stuff to be had. :grin:

#12 4RnrRick

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Posted 10 November 2006 - 10:35 PM

WOOHOO.... IT RUNS
:banana: :banana: :banana: :banana: :banana:


Was a tad bit loud :rolleyes: because I forgot to put the exhaust back on, But it runs! :headbang: Just got to trouble shoot the Tranny selector switch stuff and then I should be able to put everything back together 100% and test it. So swaping the Dash harness appears to have done the trick!

#13 daeron

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Posted 10 November 2006 - 11:13 PM

AWESOME!!!

congrats man, you just dove in and proved me right!!! these cars are pieces of cake, are they not? so many of us are so used to automobiles being pieces of something else, (:rolleyes:) that it IS hard to believe at first.....

#14 bgd73

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Posted 11 November 2006 - 04:25 PM

Excellent swap. Today. below freezing in a morning start I remember why I disliked the carb. :confused:
I have a 93 spfi from a 2wd that will swap easy enough with a bizarre harness wiring- I simply haven't found an fsm. With everything engine already plugined, uncut on harness. The only prob is ecu power , and some relays (still plugged into the harness, never hacked them)... If I figure this out, whoever is documenting can have info. All I truly need to get this going in a short time is the ID of power and destinations.
Seeing a conversion get up and going has my harness and ecu in the house, on the table, and thinning things out. :)

#15 4RnrRick

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Posted 11 November 2006 - 06:29 PM

Well the test drive today was sucessfull. All I had to do to get the 4wd light working (since the harness is a D/R 5speed harness running a PB 4wd tanny) was I had to jumper the ground wire (black) and the 4wd sensor wire (blue/red) on the tranny plugs since the tranny has a plug with 4 wires on the harness has a plug with 6 wires.

#16 Hodaka Rider

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Posted 12 November 2006 - 01:58 AM

Hey Rick, I'd like to PM/email you about something. (but can't, seeing as you have them both disabled) Go ahead and shoot me an email at miked@subarubrat.com so we can chat.




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