It’s Alive!

The engine is in and running well. It started on the first try and I now have about a 1000 miles on it with no problems. There are a dozen little fixes i need to do here and there before I say its finished but it’s good enough to use as my daily driver again.

I took a week vacation to put the engine and wiring harness in. This didn’t take the entire week as there were a ton of parts I didn’t realize I needed.

There were several tubes and gaskets related to the turbo or BPV. I had to figure out how to hook the coolant tank on the engine up to the RS radiator (I’ll upgrade that later). The power steering lines, which I discovered were cut on the donor engine, were not transferable from the RS as I hoped. I needed to get a front anti-swaybar from a turbo model to match the turbo crossmember. That was the easiest part to get as I discovered Pacific Import Auto is only 20 minutes from where I was working – one stock ‘05 STi front bar was obtained for a very reasonable price.

Still, I did a lot of work on the installation during my vacation despite the missing parts. By the end of the week it turned over though I didn’t have the fuel relay, or controller connected so I didn’t try to start it until the following weekend. I didn’t test drive it until the weekend after that as I needed to find a cat-back exhaust that would fit. Contrary to what I heard the 2000 RS exhaust won’t fit. It’s about three inches too long and the flange is rotated about 15 degrees the wrong way. So it took yet another weekend before I trusted it enough to take home. And there we are.

The  

It fits! There is a bit of corrosion on the engine from being in storage for two years but take of the timing belt covers and there isn’t even any dust. The engine had only 3000 miles on it before being wrecked.

 

I’m not completely happy with how the adaptor came out. I’m not sure I trust the strength of the pins over the long term. The extra metal pins have been removed. The white plugs in the background go to the STi ecu. The long plug is connecting to the RS plugs that previously went to the RS ecu. This allows the STi ecu to use the existing RS harness for parts that are not on the new engine (transmission sensor, fuel tank stuff… see previous posts). I only had to tap a single wire to the existing RS harness through one of the main fuses. The engine temperature and oil pressure wires go directly from the gauge cluster to the engine so I pulled the wire ends out of the plug and used some extra parts leftover from trimming the harness to make my own. I also did a cut and splice hack job on the fuel pump controller because I was lazy – so I don’t count that . Other than that everything connects through this adaptor, no soldering required.

Power Supply Routing

The main relay provides power for the ECU, several engine sensors and triggers the fuel pump on both the STi and RS. 

STi main relay wires: pg. E/G(ST)-03

1. Backup power supply. Goes to ECU plug B135 pin B19 and B61->F44 fuse box. Common with 5 and 6. Also to fuel pump relay. Switch off 10-13v, Switch on 10-13V, Engine running 13-14V.
2. Only to ECU plug B137 D17. Other end of ECU backup power supply circuit.
3. Control unit power supply. ECU plug B135 pins B5 & B6. Goes to several valves and sensors and electric throttle relay. Switch off 0V, Switch on 10-13V, running 13-14V.
4. To front an rear O2 sensors (bulkhead connectors B3 & B18)
5. Connects to 1.
6. Connects to 1 after B61. Also to data link connector.

RS main relay wires: pg. 36 Wiring

1. Ground.
2. ECU B135 pin B19. “Self-shutoff” control.
3. Control unit power supply. ECU plug B136 pins C1 & C2. Same as STi 3.
4. To front and rear o2 sensors (engine connectors E24 & E25). Same as STi 4.
5. To pin To fuse box B61/F44 and ECU B136 pin C9 – Backup power supply. Same voltages as STi pin 1.
6. To pin 5

Pins 1 and 2 control the relay. The voltages are reversed between these pins on the
RS and STi and pin 1 on the RS goes to ground instead of back to the ECU.

STi relay pin 1 will tap RS ECU wire B136 pin C9 which goes to fuse box via B61/F44 and on to the positive battery terminal. This wire also goes to STi ECU plug B135 pin B19.

pin 2 will go to the STi harness -> ECU.
pin 3 to the STi harness -> sensors and stuff.
pin 4 to the STi harness -> Oxygen sensors
pins 5 & 6 connect with pin 1.

 So, I will use the STi main relay and leave all the wires intact except for pin 1. That will splice into the RS ECU wire B136 pin 9 (which also goes to STi ECU B135 pin 19).

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I’ve got every item from the remaining list except one of the O2 sensors and an old impreza ECU arrived today.

The big table…

Here’s the table I’ve been working from. This table maps every 2004 STi ECU wire to every RS ECU wire (except for the couple engine to elsewhere wires). This also includes which wires will be blended from the RS harness into the STi harness. There are a couple question marks, particularly about the main relay. I’m almost set on buying another 2000 RS ECU, pulling the plugs, and doing all the blending between the RS ECU plugs and the STi harness so I don’t have to cut anything in the RS.

2000 RS to 2004 STi ECU Table

Still goin’

I’ve removed every wire in the harness that doesn’t connect to the engine or the ECU. All but about two of the wires from the engine go directly to the ECU and those both go to the combination meter for water temperature and oil pressure warning light.

On to phase 2: 

 There are a lot of wires that come from the ECU but do not go to the engine. Most of them, I think, will be spliced with the RS wiring but there are some, like the fuel pump controller, that do not exist in the RS harness. My next step is to make a spreadsheet of every STI ECU pin and map it to every RS ECU pin. I’m debating buying another RS ECU, ripping out the connector, and building an adaptor like they make for Honda swaps. Since it only takes about 3 hours to pull out my RS engine it might make emissions a little simpler…

 About that, I have talked with the department of ecology on how emissions testing will work with a swapped engine. Contrary to what I’ve read on local forums (Seattle area) the car WILL NOT be tested as a 2004 STI but will need to pass 2000 RS standards. This is true even if all the OBD2 wiring and emissions systems are intact. I was told by a testing station operator and two people at the department of ecology that connecting the 2004 STI ECU to the testing equipment will register as tampering and automatically fail the test before it even starts. Fortunately, I have also been told I have the option requesting a “sniffer” test, but I will need to contact the Washington State Department of Ecology before hand. They will then notify the station manager of the situation and how to test my car.

Parts I still need (at least)

1. Fuel pump controller and wiring.
2. Front wiring harness – (might make my own)
3. Gaskets for VF-39 turbo.
4. BPV gasket.
5. STI 02 sensors.

C3-PO evisceration scene – Take 2

I removed quite a few wires last night. Most came from clearly nonessential systems like the fan controls, stereo, lights, and doors though there were just a few wires that connected to the ECU. I made a minor mistake here in not labeling those wires when I cut them. They’re not engine related, and will be merged with the RS harness, but now I have to trace them to the ECU connector pins and identify them. Again.

I should have the relay, fuse box and ABS out next time I get a chance to work on it. That leftover pile is getting pretty big

    

2004 STI Engine into 2000 RS Engine Swap

This blog is to chronicle my 2004 STI engine into 2000 RS swap. This swap is in progress and I am currently trimming down the bulkhead wiring harness from the STI. This involves identifying all the engine related wires and cutting out everything else.

Everything else includes things like the radio, ABS system, wiper controls, door wires, air bags and heater controls. I will be using the RS transmission so the DCCD stuff is out too. (Hmm, I should make a complete list…). Eventually, I’ll be left with an engine only harness that plugs into the STI ecu (using the STI plugs). I will then cut the wires from the RS harness for the non-engine functions and solder them to the STI plug wires. There are a few exceptions to this rule (I think) so for now I’m only cutting what I know for sure I don’t need.

All I know about how to do this swap I’ve learned from the NASIOC forums, the powerlabs.org site and hours spent reading the 04 STI service manual. I’ll post links soon. This blog will duplicate some of that information and include specifics for an 04 STI swap.