New Alltrac Owner Project

Things to try first

  • Wiring harness

    Votes: 3 60.0%
  • Distributor

    Votes: 0 0.0%
  • Bad Ground

    Votes: 2 40.0%
  • ECU is shot

    Votes: 0 0.0%
  • ICM or something technical with the ignition

    Votes: 0 0.0%

  • Total voters
    5

TomatoSupra

New member
Hello everyone. I'm going to post all my project stuff here, and hopefully keep everything organized. Now keep in mind i am VERY new to turbo vehicles, and project cars. All of the cars i've owned so far ran and drove before i bought them.

Ok, for a little background, the car is a 1990, 80K on the odometer, has a 3rd Gen 3s swap, (HKS mushroom intake, 3 inch turboback exhaust) and the owner did the swap and was unable to get spark. Car turns over, and sounds like it has good compression.

11749332_10206717695442194_235064117_n.jpg

11778110_10206717667361492_772479134_n.jpg

My goals right off the bat.
1 - Get it running (Duh)
2 - Get it driveable (Wheels, tires, rotors, brakes Ect)
3 - Last but not least, get it all cleaned up and pretty. (Fix cosmetic stuff, put radio in it, ect)


So here's all the info i have so far on why its not getting spark.

Previous owner tried swapping distributors with another 3s, and tried swapping ignition coils. Also tried plugs, wires.

My main goal tonight, is to get the numbers off of the ECU in the car, and find a wiring diagram for it. I had a buddy of mine message me right after i got it and said that i need to "Re-pin the engine to body harness", so it sounds like i may need to get pretty technical right off of the bat.

Once i verify his wiring job on the harness, i am going to move in the direction of Easy/Cheap to Hard/Expensive. Hopefully it won't take me that long to get it figured out, and i can get it up and running this winter.

Like i said earlier, any advice, comments and questions are welcome and appreciated!

Dan
 

zaluss

Member
I had the same issue with my 3rd gen swap but without knowing who the did the wiring, it could be anything. I would start with checking the 12v to the ignition coil and igniter. If theres no 12v, check the grounds. If everything checks out, you gotta bust out the wiring diagrams.
 

plourdem14

New member
I had a similar problem but it was with a 2nd gen. Like the guy above me said not knowing who did the swap it could be anything. In my case just some engine bay wires that had become brittle and lost connection. I have a few more kinks to work out but that is what it came down to for my no spark issue. Check any clips that are related to the spark system, wires coming off the fuse block and I'm sure if a 3rd gen has one but there is a plug coming off the bottom of the dist IIRC in 2nd gens, that could be worth a look as well. I guess if you don't find anything you could methodically go through and check continuity of wires related to the system as well. If it's body harness wiring it shouldn't be too bad I'm sure theres at least a few guys on here who have done your swap and can point you in the right directions and probably even get you diagrams.

Good luck hopefully it works out.
 

Street_Chally73

New member
Congrats on the recent purchase! It looks like a relatively clean car and hopefully you're able to figure out the no spark issue without dropping too much money. GL!
 

ChrisD

New member
Congrats! Always interesting taking over on a project. I'd run through the engine bay to see if there was anything obvious, then check the ecu pins to double check what exactly they did there. And yes since its unknown, check was ecu they are using too. Have fun with it!
 

760gt4

New member
If your troubleshooting leads you to a bad wiring harness and not a fault ignitor, coils, etc, the easiest and maybe fastest way to get it running would be to send your harness to Wiregap and have him fix it for you and in the meantime address any other issues you may have. Once you get your harness back, plug it in and it should be up and running.
 

TomatoSupra

New member
760gt4":q94b87io said:
If your troubleshooting leads you to a bad wiring harness and not a fault ignitor, coils, etc, the easiest and maybe fastest way to get it running would be to send your harness to Wiregap and have him fix it for you and in the meantime address any other issues you may have. Once you get your harness back, plug it in and it should be up and running.

That's a good idea. However, i would have to call and make sure that they do this swap. But if it comes to that, that's what i'll do.
 

760gt4

New member
He's done that swap countless times. Go to wiregapinc.com and you'll see most of the swaps he does.
 

TomatoSupra

New member
760gt4":2ee8wlj9 said:
He's done that swap countless times. Go to wiregapinc.com and you'll see most of the swaps he does.

I didn't see it in the pricing sheet, but im sure if i call they will say that they do that.

So im guessing i just need the ECU serial, the Motor Serial and send my harness in to him?
 

760gt4

New member
Just tell him exactly what you're trying to do. He usually needs the new engine wiring harness and the stock engine harness, and he'll merge them. You won't need to send out your ecu. He's done just about every swap into alltracs and mr2's so you should be good to go after he's done with it.
 

msanders2

New member
Another MRP alltrac!!!!!!

You don't have to send Doug 2 harness' you can just pull the one off the guy who tried to do the swap has on the motor and If there is anything wrong with it Doug will fix it.
 

TomatoSupra

New member
Thanks for the advice guys, I actually think it will be more of a pain in the ass to take the harness off, but if it has to come to that, then it will.

Yesterday, i had a few minutes, and managed to get the ECU out, and snap a picture.

1. Is the this right ECU i should be running?
2. How can i find the wiring diagram for it?


ecu resized.jpg

Thanks!
 

TomatoSupra

New member
underscore":1c49j7k7 said:
The part number says it's a JDM ST205 ECU, so that should be the right one for the swap.

Awesome! OK, so that's the first step. Just to confirm, i just need the ST205 wiring diagram, and the diagram for the st185 body harness correct?

I also noticed when i took the ECU out, there was a wire dangling from the harness, like not plugged into anything. I think i am starting to believe that the wiring is the issue here. The good news is that none of it looks hacked apart, or torn into, so i should have a "good" harness to start with.

Thanks for the help!
 

underscore

Well-known member
That could be the wire for the speed signal to the ECU, since Japanese cars are limited to 180km/h by the ECU a lot of people disconnect or modify this signal to remove the limit.
 

TomatoSupra

New member
Alright guys, its been a while but its time for me to kick this project into gear. I will be much more active now, and will be taking a TON of pictures, and spending a lot of time on here.

My first round of troubleshooting tasks starts this weekend. I was unable to verify i had the correct wiring diagrams, and even unable to verify i indeed had the correct wiring harness for this motor. It seems like the best option for me on this is to send this puppy into Dr tweak, or someone similar and have it rebuilt from the ground up, to make sure that i have the correct stuff going into to, or to have someone troubleshoot with me that knows the harness and motor well. i had someone on facebook who looked at the car before me tell me that it was the incorrect harness for the motor, which makes me scared that i would have the wrong diagram and make it worse than it is.

To get the harness out, this means either 1, i pull the motor and take the harness off that way, or 2 i crawl around underneath it for a weekend and try and weasle it out. If i take the motor out, I can do some other stuff like the water pump, verify the timing and start making sure everything is installed and connected correctly. This may help jump start my knowledge of this chassis, and motor and may prove to be better long term, but i would obviously rather do it the "easy" way to begin with.

First question, which is easier? And which makes more sense?

Second question, do you guys agree with my choice to start fresh with a brand new harness? Or once i have the harness out will it be easy to tell if its an st185 vs a st205?

Third question. If you guys have any more information you want to send my way, it is VERY MUCH appreciated. I want to try and do this myself, and do not want to end up shipping it off somewhere and having someone else fix it.

Thanks again guys,

Dan
 

TomatoSupra

New member
Hey guys, sorry. It's been a long time since ive posted here.

Found the issue with the car. It was a bad fuel pump caused by a rusted fuel tank.

I removed the fuel tank and replaced the pump and filter, and she ran great for a weekend. Now i believe the left over rust in the tank clogged up the filter again, and she's back on jackstands.

Anyway, just figured i'd share the news, and its also for sale currently. Sounds like some people really like it and are interested in buying it, so i may be getting rid of it.
 

TomatoSupra

New member
I'm Back!

Things that have happened since i've been away.

EDIT - My last post was about the rusty fuel tank. I had that professionally restored by a place in MN called FuelTankRenu. Put a new Bosch fuel pump in her, and she purrs like a kitten. 8)

Car runs and drives. Went on a few trips, most less than 20 miles and had small issues every time. I did, however, have a small coolant line around the drivers side that popped off and sprayed coolant all over the ground. Fixed this, and compression tested the cooling system and all seems well. :D

I should probably test the HG to make sure the little heat up didn't pop the gasket.

Fixed the small coolant leaks, and then it was driving fine. I finally decided to push it a little bit, and it seemed when the turbo really started to warm up, the temps kept rising. Never to the red, but fluctuation that way.

Current Status,
I ordered a new Aluminum radiator, along with an intake coupler for my HKS intake and a new Thermostat.
Took the W2A intake back off. I want to shorten the pipes leading to it, and verify it's not full of Gunk.
Noticed that when i was running a temporary intake (1.25" PVC and a small air filter) a little bit of oil was being seeped out of the compressor side of the turbo, and the blades are a little dirty. I'm going to assume this is due to the restriction the intake was putting on it. I'm going to clean it up, and verify it stops with the less restrictive intake setup I will be putting on.
I closed off all the vac lines that were not being used, all were for the evap system that's not installed anymore.
CEL is on, so that's next after the cooling system has been overhauled.
The front suspension is quite a bit lower than the rear. Assuming this is due to bad springs or struts. This fix will happen eventually.

The goal is to Autox this next spring, so i'm going to need a lot of parts, and expertise over the winter. For the first time in 4 years, i have my car at my place of residence so it'll be SUPER easy for me to work on this winter.

I'll grab some pictures and post them up here so you guys can see what's going on.

As always, I'm open to suggestions and tips on all of this.

Dan
 
Top