ECU Swap

[Jammy Johnny]

Well I have not been active for pretty much 2 years due to a bad ilness and the Subaru has just lay there all that time (until a few weekends ago) . I never got around to sorting out the misfire before I was ill.

The car is an Impreza 1997 UK turbo 2000 

But now I am fit again, I have been working on the car. I have now fitted (some fitted before ilness) new coilpack, HT leads, Plugs, MAF, Injectors, Timing belt kit, Fuel filter , Had inlet manifold off and resealed. I also did a compression test and all cylinders and showing all close to 150 psi.

I still have the misfire at around 1200rpm and the back firing and not as quick as the car should be.

The car has a full decat stanless exhaust system and I am unsure it it ever had a daughter board fitted to the ECU.

My question is... Will I be able to swap the ECU for a direct replacement for that model and year ? and is it possible for that ECU to cause problems with a misfire in one cylinder and also a rich mixture on the other three ?

I have managed to aquire an 8s ecu, but how will that go with my immobiliser fob. Now I know why I was ill lol.

Best wishes

Johnny

[savage bulldogs]

Have you checked to see if it has got a esl daughter board?

If not unplug the ecu and whip the casing off . It should look like this

If the ecu hasn't got a esl board, do a ecu self code check, to see if there's any fault codes stored and reset the ecu .There's a "sticky thread " in the how 2 section [emoji6]

What colour are the injectors? As they should be grey 380 cc ones .

If it's not broke .....upgrade it 😊

[Jammy Johnny]

Cheers for replying savage. I do not use the black wires because I have an adapter for the yellow socket that converts it to OBDII. The ECU is reset and there are no stored codes. 

I have not checked for an esl board yet, but I will do at the weekend when I get to work on my own car in the garage at my work.

The injectors are grey 380cc's and I have replaced all of them.

can anyone confirm it the injector wires for cylinder 2 on my age of car are light green and yellow and cylinder 4 are blue and yellow wires 

This misfire has been on this car since I got it 2 years ago and now that I am not ill, I would like it sorted so the car is drivable. The annoying thing is that I am a mechanic and I diagnose and sort cars for a living, mostly diesels though lol.

 

[savage bulldogs]

The light grey injector plugs on each bank go to the front (cylinders 1 & 2) .

The dark grey plugs go to the rear (cylinders 3 & 4 ) .

I can only find 1 pic of my v3 uk engine showing the passenger side and it only shows cylinder ,which has a light grey plug with yellow n green wires .

Are the ht leads plugged in the right order ?

If it's not broke .....upgrade it 😊

[Jammy Johnny]

The HT leads are in the correct order. Lovely engine you have there mate :)  And I see the cylinder two injector wire are green and yellow. 

I will have to test the pulses with a test lamp on the injectors to see if they are getting a signal.

 

[Jammy Johnny]

Well the ECU has no ESL board fitted so that is not the problem. And the ECU I got to replace it will probably have to be coded because I get code 53 for immobiliser when its fitted.

The engine is running really rich to the point that it stinks of petrol.

I did notice today that while the engine was running rough and back firing at tickover, If you unplug the wiring from cylinder 3 the engine sounds and runs without backfiring So I thought I has found my misfire. Changed the injector with a good cleaned one and it was still the same, backfiring and rough idle but unplug cylincer 3 and runs better. pulling the injector wire off either 1 2 4 pulls the engine way down. I am at my wits end with this thing now. Any ideas are most most welcome.

Best wishes,

Johnny.