viltronic

Hello there,
I am new to the Scoobynet forums, forgive me if I am not addressing my issues in the correct forum.
I am looking for some information regarding my GF8 96 wrx Jap import wagon.
Having owned it for about 6 months now, I am still battling inconsistent performance.
(Random sluggish acceleration, as though there is a sock in the intake system)
It has run beautifully for a few days in the time I have owned it, giving me the ultimate inspiration to get this baby ripping consistently, other times simply random performance...
After replacing almost every sensor, plug, fuel system, clean injectors, etc. I am seeking some information on the ECU replacement, it is my last resort!
The current ECU is a 3B, standard intake, exhaust, with a MBC set to around 13psi (just below the fuel cut)
I have my suspicions the ECU has issues, hence my research into a budget friendly replacement.
Through numerous forums I see the Z4 is an option for this, I am wondering if it will be a "plug and play" setup, or will lead me into a whole new bag of upgrades to make it perform.
Any insight or links to forums or ECU alternatives I have missed would be MUCH appreciated.
Regards,

Tidgy

have you had it looked at by a specialist and has it been dyno'd to diagnose the fault?

yabbadoo4

iTrader: (8)

turn the boost down bud. maybe you are hitting boost cut. or fit a fuel cut defender.

viltronic

"have you had it looked at by a specialist and has it been dyno'd to diagnose the fault?"

Yes, I have had a lot of diagnostics without any success so far.
Dyno is the last step, however as it is inconsistent, there seems little point to waste 200+$ on a dyno to simply read A/F ratio and power output.
The ECU to my knowledge is non-adjustable, hence me rather spending the same amount of money on another ECU (Z4 if anyone can inform me of its suitability) to see if that is the problem and potentially have some better mapping/higher fuel cut/boost
I have replaced:
Knock sensor
MAF sensor
O2 sensor
Fuel pump (now walbro)
Fuel filter
Air idller
Spark plugs
Turbo inlet plumbing
Air filter
Injectors ultra-sonicly cleaned/flow tested
New timing belt/water pump

Have had checked by specialist:
Smoke flow testing, no leaks in intake plumbing
Ignition system
Fuel pressure regulator

"turn the boost down bud. maybe you are hitting boost cut. or fit a fuel cut defender.'

I have ran the boost to the fuel cut (not on purpose), then backed it off again.
Currently running about 13psi, the 3b ECU should be good up until 13.9 (if what I have read is correct) before the fuel cut will kick in (a very obvious cut...)
As far as I know a fuel cut defender will only mask the problem, fuel/timing maps will still not be suitable for higher boost, hence my research to replace the rather mild 3b ECU.

Can anyone recommend a budget friendly standard ECU replacement with a more performance orientated timing/fuel mapping?
I have seen some Z4's for sale second hand at a reasonable price, will they just plug in to the same loom?
Any information on compatible ECU's that I could use as diagnosis/slight upgrade would be much appreciated.

Tidgy

dyno does more than just read ARF's, a decent operator prob could have saved you changing all those sensors

you can get your existing ecu mapped though, ESL daughter board.

JTinnovations

iTrader: (2)

Any error codes read as part of the "lot of diagnostics"? Sounds like it's going in to limp mode, dropping the boost. Have you got a boost gauge that would verify this?

When I had a 1998 UK turbo it had a strange issue if you accelerated from a certain rpm in 2nd gear - it would drop boost deliberately as part of some emissions test it needed to pass. I doubt that it is present in a) an earlier model and b) an import but thought I'd mention it just in case - is there a repeatable circumstance when the fault occurs?

viltronic

I will look into the ESL daughter boards, thanks

viltronic

Yes, the O2 sensor and air idle codes were originally triggered, now there are no error codes after addressing such issues.
It feels like the problem is timing related, after an ECU reset the car quite obviously learns its timing, sometimes learning a decent advance, sometimes just being f8cking retarded...
I know it thinks it is doing it for safety, steering away from detonation, however I dont think I have ever heard it ping...
This is why I am interested to diagnose the ECU by getting a replacement to compare it with.
Does anyone have a spare 3b ECU lying around the place??

Turbotits

iTrader: (2)

Youd struggle to hear a subaru engine ping by ear. What type of fuel are you using and is it always the same stuff?

viltronic

Always 98ron, also tried octane boosters. Cheers