1986 GL carbureted to 1988 SPFI plug and play?

[firehawk618]

I have an 86 GL wagon that came carbureted.

I scored the whole harness off an 1988 Sedan that had SPFI.  

I took everything and fished it all back through the dash.

It's actually pretty easy to get the whole thing out as a unit without cutting anything.  I was quite surprised.   After looking under the dash I thought there would be some cutting involved but nope, it all unplugs.

My question is.  I cannot find a COMPLETE wiring diagram for an 86 nor can I find a complete one for an 88.

I have found the service manuals that are posted online but they only seem to show the whole engine wiring harness.  They don't really show the dash etc etc.

Has anyone done this exact swap?  My concern is the big black and big white plug under the dash.  I confirmed they both plug right in but will I need to move some pins around for the car to run?

I don't care about the CEL *my car didn't come with one and things like that.  I just want to confirm that by plugging this 88 harness directly into my 86 harness that the car will run.

The reason I'm asking is after plugging everything in I wanted to do a quick test and sprayed some ether in the throttle body and cranked it over.  I am not getting any spark.

It was getting dark so I bagged it for the night and have done zero troubleshooting.

 

I definitely have everything plugged in where it needs to go and  all ground rings are fastened.

My biggest question would be if anyone has done this complete swap and did it just plug right in.

I have found the EA81 to SPFI conversion how to's but have not found a single one for EA82 carb to EA82 SPFI.

 

Thanks for any input on this guys!

 

[DaveT]

I have original printed factory service manuals for 1986 and 1990.  They include complete schematics for everything, and the different models.  Not sure why they don't seem to be online....

 

There may be a few differences under the dash, in the combination meter, but I have not ever traced into the differences that far.  If you have the dash harness from the 88, you should be all set....

 

The CEL isn't a big deal, as far as getting it to run.  But it can be helpful to let you know when a sensor is bad, etc.  which can sometimes help with troubleshooting.  It's all tied into the ECU anyways.

[DaveT]

OH! did you grab the fuel pump from the 88?  You need the high pressure type for SPFI.

[firehawk618]

DaveT, yes I have the SPFI fuel pump.

At this point my only concern is that mating the 86 dash harness to the 88 SPFI harness will result in a car that starts!

I can work out the details on CEL and any accessories that may not work after the fact.

I guess when I dig into it again I will just do it the old fashioned way and start verifying power at the right pins of the ECU and various components under the hood if no-one has chimed in before then with the results of this type of swap.

Worthwhile note:  The car I got this all off of was perfectly straight.  I have no idea why it had become a parts car......

Perhaps it quit running due to a bad distributor or igniter?  We shall see!  I do have a spare igniter but do not have a spare distributor.

[firehawk618]

Dave I forgot to ask.  Do those manuals show the complete schematic on one page?  If so is there any way you could scan that page and email it to me?

It would help a ton if I could see each and what exactly pinouts are different at those connectors.

There's definitely difference between the two pinouts but I suspect the differences are things like CEL and other optional items.  I am hoping the critical ones are all in the right place.

[DaveT]

I will have to look a little later - let me know the model and all for both cars.

 

DL /GL, wagon, sedan, 4wd, California.

[firehawk618]

I will have to look a little later - let me know the model and all for both cars.

 

DL /GL, wagon, sedan, 4wd, California.

 

 

1986 GL Wagon 4x4, d/r 5 speed.

 

1988 ?? Sedan.  FWD 5 speed

 

Thanks for anything you can offer.

 

I am probably going to swing by my local library and see if they still have old manuals.

 

It's been a decade since I have gone there for auto manuals but back then they had GIANT shop manuals that had extremely good diagrams for a bunch of old cars.

[firehawk618]

For the record the two are most definitely NOT plug and play.  Yes all the connectors *except one* are there and plug directly into each other but after thorough examination the pinouts are changed a whole bunch.  To be truly plug and go you will have to have the dash harness out of the SPFI car.

I am heading back to get the dash harness now and that should do the trick.

The one connector that is missing on the body side of the carbureted 86 is connector F98.

It's simply not there and carries several critical wires for running the SPFI.

Just one difference for example.  The oil pressure gauge wire goes through this connector in the 88 but NOT in the 86.  This isn't critical to make it run but I'm just trying to express there are major differences.


At this point I have to wonder if I should have just built a harness out of the one I already have.

Meh what fun is that!  I guess I now get to pull two dashboards!  The bright side is the first dash I'll be pulling is the scrap car so I will get to learn off of that one and hopefully that will prevent breaking my dash!

[firehawk618]

Ugh a thought I just had. 

Since the wiper / blinker switches changed from 86 to 88 that means that I will not be plugging directly into my existing wiring / switches.

Besides the wiper / blinker / hazzard switches moving around what else is different on the dash board between the two years?

I really got no issues with cutting / adapting those switches to make them work.  

I think over all this will be the cleanest / easiest way to finish my conversion considering I already have the whole engine side harness installed.

Thanks!

[DaveT]

yes, get the dash harness. 

 

changing the wiper switch stuff should be less of a deal than the engine stuff...

 

I have access to a large scanner, but not until Monday.  Some of the schematics are big fold outs.

 

I have changed a fwd to 4wd which is a lot simpler, but having manuals for 86 and 90 along with extra wiring from a few other similar cars helps a LOT.

[firehawk618]

Greed Dave.

I got the dash harness.  I have it installed.  The car fired right up.

Now to just work out the switch and cluster lamp differences.

I'll let you know later this weekend whether or not I'll still need those diagrams.

I have a feeling i'll have most of it ironed out by the weekend.

The way the switches attach to this column is totally different than how they attach to the newer column.

I'm probably just going to splice my existing plugs into the new harness to make it all work.

I still have a bunch of dash wiring work to do but the dash is back in and the car did run with some ether in the throttle body!

Now to finish adapting my fuel lines near the tank / under hood and see if she runs.

[firehawk618]

Fueling all done.  Fires right up and settles into a nice idle on the first try!

All that's left for now is to iron out headlights, blinkers and HVAC fan.  My forte!

[firehawk618]

HVAC blower motor done.  Re-configuring the pins on the plug did the trick on that one.

Wipers done.  This was far more complex than the blower motor was.   The 86 has the delay brain built into the switch.  The 88 has a stand alone brain for this.  It took some creative re-configuration of the pins along with strapping a couple wires together.  They work as they should now with the 86 switch.

Turn signals, looking for a GOOD diagram for the 86 on this one.  

Headlights / parking lights / dash lights up next.

Edited March 6, 2016 by firehawk618

[firehawk618]

Done, done and DONE!

Had a CEL immediately and it was the EGR solenoid.  Imagine that.

I had a spare one and tested it.  It's bad also.

I just took one of my spare relays from the 86 dash harness and spliced it to the EGR solenoid connector.  Reset codes and the ECU is happy now!

The only things I have left to do are get a hold of a clutch switch to prevent the neutral code and install an O2 sensor which is on order.  I plan on straight piping the car at the same time as welding in the O2 bung.



For anyone who stumbles across this.  Do not do this conversion.  It's about as far from plug in and go as you can get.

If you swap over the dash harness then it will fire up and all BUT then you won't have blinkers, headlights, heater, 4wd indicator, 4lo indicator etc etc.

It would likely be easier to just strip the ECU parts off the 88 harness and make it run that way.

If you can get the whole steering column out of the 88 along with all dash switches THEN this may be a plug and play deal but I couldn't get those parts for free/cheap so I was determined to make mine work.


Some substantial differences are:

Turn signals.  Besides the switches / connectors being completely different the whole way it works is different.  The 86 has the turn signal relay built into the switch and the 88 does not.  The 88 has a stand alone relay.

Headlights.  The connectors are totally different because the 86 has the headlight switch on the dash and the 88 has it integrated with the turn signal switch.  It can be made to work if you are REAL good with schematics / wiring.

Heater.  The fan wiring is different.  This was a pretty easy fix.  It just took swapping some pins around at the connector.

Indicators on cluster.  This dash harness had the 4low pin at the cluster but this wire / pin was missing at the body connector on the passenger side.  Where is this wire?  Beats me.  Probably taped up in the dash harness somewhere.  I just farmed this wire from my old harness and slapped it in.

4wd light can be made to work by cutting the plug at the transmission and connecting the appropriate wires to the 86 switch on the trans.  Same with the reverse lights.  The 88 connector is totally different again.


There were other things I had to work around but all in all it's done and it runs so much better than it did before.

[firehawk618]

Welp got an EGR code immediately upon starting the car up.  Of course the solenoid was bad.  I had two more laying around and when testing the resistance on them they're all bad lol.  All have opened coils.  Totally shot.

I also have a total of 3 Evap solenoids.  Wouldn't ya know all 3 of those are also shot.  They also test as open when checking resistance.

I initially just snipped off two random relays from my old dash harness and spliced them in place of the EGR + EVAP and the codes went away.  I didn't like that so I pulled those off and installed little dashboard light bulbs in place of the relays.  LOL works perfectly.  ECU sees some resistance and keeps it happy!

So after those codes were taken care of after a couple miles I got the neutral switch code.  I had installed a switch on the clutch and plugged it into what I thought was the correct connector as it was right by the clutch pedal.  BZZT wrong answer.  For some reason I was thinking this neutral switch was a clutch switch.  It's not.  After a little research I figured out it's a wire that goes to the transmission.  I simply pulled an ECU pin off my spare harness and rigged it to a connector to the clutch switch.

ECU happy now.  No more neutral code.

Now I can go 10 miles and it throws a new code.  Speed sensor code.

Sooooo I pulled the cluster, verified I have continuity from the right pin on the cluster to the correct pin on the ECU.  I then pulled my speedometer head.  I found the reed switch but it's encapsulated in plastic on the speed head unit.  Damn.

I tested it with my meter and it's just stuck open.  No amount of spinning the speedometer input changes that.  Waving a magnet near it does nothing either.

Oh well, tomorrow my O2 bung + sensor will be here and i'll be installing that.  This weekend will be a trip to the bone yard to salvage a speedometer head.

I can't remember ever having a failed reed switch on anything...ever.

Anyhow once I get the speed sensor code fixed I have to wonder what code will be next!  LOL


oh yeah.  My car runs great.  Idles fine and accelerates good when past 1/2 throttle however when cruising or under light acceleration it kind of chug a lugs.  It feels like it's going lean.  I can roll into the throttle more and it clears up * I assume it goes open loop when it clears up.

 

I thoroughly tested and set the TPS according to the book using a feeler gauge.

I then cleaned my MAF sensor and it made no difference.  I swapped in a spare MAF I have, no change.

I picked up a throttle body gasket and pulled the TB.  Took the IAC off it, cleaned it thoroughly *totally unrelated to my drive ability issue* and in the process of removing the IAC it dawned on me.  I had never noticed the two vacuum ports on it.  One goes to the EGR system which is still all in place *although the solenoid is bypassed* so it shouldn't be leaking in un metered air on that circuit.

The EVAP however is missing the charcoal canister.  I checked the 3 lines after installing the SPFI and only one had vacuum when sitting at idle so I capped it.  What I didn't realize is the other hose gets vacuum when at part throttle!  There was my source of un metered air and explained my drive ability issue.

I went ahead and yanked off all the vacuum lines / solenoids.  The only vacuum hose I have now goes to the HVAC system in the car.  The other ports are all capped off.

Went on a test drive.  The problem is 99% better!  I am happy.

I'm hoping that installing the O2 sensor tomorrow will smooth out the rest!

[DaveT]

The oem solenoids are notorious for failing open. I replace them with ones from toyota. I came up with that mod around 1989 +-. Still using the same ones that I bought at a junkyard back then.

[firehawk618]

The oem solenoids are notorious for failing open. I replace them with ones from toyota. I came up with that mod around 1989 +-. Still using the same ones that I bought at a junkyard back then.

Yeah I gathered the fact they're a very high failure item on these forums!

 

I was initially going to leave all the smog crap in tact and give it a chance but when all the solenoids I had are bad right from the get go that made it very easy for me to just tear it all off.  Sure frees up some more room!  I like the light bulbs to pacify the ECU and let it continue checking everything else.

 

 

I found a speedometer head at the local pick and pull.  Brought the head home and put my VOM on it and crap, it's stuck open also.  Hmm maybe I'm doing this wrong.

 

Since the book says look for 2v pulses as the speedometer turns I decided to just put a 1.5v battery on one end.  Sure enough when I put a battery in line and set my meter to volts it does open and close as the cable rotates!

 

Back to my original one.  Tested it this same way and nothing.  Stuck open.  Phew, not a wasted trip to pocket and pull.

 

Slapped the new speedometer head in.  As soon as I started driving the CEL shut right off!  

 

Now if I can get through 1-2 days without another code I will feel like all is working as it should!

 

 

Sure strikes me odd that this ECU will get hung up on one code and just stop testing everything else.

 

First it was EGR solenoid.  It would only throw that code. Nothing else.

 

Fix that then it proceeded to the neutral switch code.  Ok hook one up.

 

Next thing was the speed sensor code......

 

 

Edited March 10, 2016 by firehawk618

[DaveT]

They are supposed to log more than 1 code at a time.  I may have had 2 at the same time once or twice since 1988.  Supposed to blink them out sequentially.  I have not seen a failure of that speedometer sensor.

 

EGR & Evap mods:

 

http://www.dynahoedave.co.nf/solenoid.html

[firehawk618]

I agree that the should and will report more than one code at a time however it appears "as was mentioned somewhere on here" that certain codes will cause the ECU to stop testing any farther.

On my car the EGR solenoid code caused it to ignore the neutral switch.

Once that was fixed the speedometer was ignored because the neutral switch wasn't hooked up etc etc.

In all my years working on various electronics and stuff this is the first reed switch I have seen that was completely dead.

[firehawk618]

Holy smokes.  Looked at some of the Subaru stuff on your website.

I am VERY glad I live in a region which has no rust issues!  These cars sure seem to rot right out.

[DaveT]

You definitely have to stay on top of it to keep them around.

[firehawk618]

Hollowed out 1st cat.  Discovered 2nd cat was already gutted.  Threw all heat shield in trash and welded in o2 sensor.

While I had it up in the air pulled both those exhaust air tube things, cut them down to a nub and welded them shut.

Man this thing leaks oil like crazy.  It's so messy under the car.

Perhaps I'll pull the engine soon and put all new seals / gaskets in it.

[firehawk618]

I also put a new clutch cable in.  WOW what a difference that made.  The old one felt fine off the car but under a load was extremely stiff!

[firehawk618]

Well my time spent with an EA82 powered GL is going to be short lol.

 

I was going to run the EA82 until I could kill it however the other night I was on a stretch of I5 which is 70mph and this car would barely hold it!  That was on flat ground.  I wanted to go 80 and it just wasn't going to happen ROFL.

I sourced an OBDii EA82 wiring harness today *what a nightmare to pull that is!* and got it all stripped down to the bare essentials.


I chose OBDII so I can use all my scan tools in the future for diagnostics.

I will be running only what's needed to run. No EGR, no 2nd o2 sensor, no EVAP etc etc.

By next weekend I will have the engine here and I will put all new gaskets / seals in it before it goes in the GL.

 

Time to order an adapter plate and clutch.


On the clutch note I do have a question that perhaps you can answer.

I found the EA81 to EJ22 write up however I have yet to find definitive answers as to what combination of clutch I should use?

XT6  PP and disc?

XT6 PP and EA82 disc?

Any input is welcome on this one.  I will be running mudders and a lift so I would like whatever clutch goes in it to hold.

Thanks!

Edited March 14, 2016 by firehawk618

[josolong]

hey i'll give you a bump and say thanks for responding to my post. this is some good info for me so far as the particulars of wiring the swap go.

 

good luck with yours doggie, sounds like a handful. i'm still gauging where i'm coming into the process at with mine.