Hey guys, im having a few problems with my 93 import wrx, the only thing really i ve yet to change is my ECU, i ve just been out and had a look at the one in the car, and its label is blue and has a big U8 on it, it also has another sticker, presumably from a tuning company, which says "works garage" REDZONE... can any one shed any light on this,, is this the correct / standard ecu, wot should i replace it with???

any help would be most appreciated

thanks

 

come on... anyone???

 

do you know what boost your running with this ecu?

sounds like it's probably chipped!

 

it only runs 1.0 bar...

its the boost im having problems with

sometimes it only runs 0.5 bar

its not the boost solenoid i ve tried 3 of these, and even a manual boost controller, still same fault.. any ideas???

 

what kind of problem

 

sometimes it does it sometimes it doesnt, it is not related to time of day / amount of fuel in tank / temperature / load...

drive along.. put foot down...feels like hit brick wall (boost cut??)

but some days you can drive miles and miles on full boost and its perfect, some days you cant even get to rthe end of the road and it only gives half boost.
so far have changed..
plugs
coil packs
intercooler/pipes
boost solenoid
map sensor
air intake pipes
maf sensor
fuel filter
fuel pump

gettin really annoyed now :-(

 

if its a really aggressive judder, it sounds like feul cut...considering you have checked everything else, and around 15 psi is where you would prob hit it too

 

wot causes fuel cut? sometimes you only get to like 10-11 psi and it does it..

 

the ecu/mapping determines when the car momentarily shuts off the fuel. (its a safety thing) There are ways around it like FCD, remap, or new ecu like a PFC

 

so it might be worth changin the ecu next? is a U8 a standard one for my car?

also sometime when you go to pull off it hessitates and you hear a couple of clicks (relay)? under the dash drivers side..

 

U8 i think is standard for your year yes, im sure it came just before the Z4

not sure about the clicking, check your cam position sensor is on tight and clear of dirt see if that helps the hessitation

 

cool , cheers mate

 

does anyone know what a w9 ecu is off, will it be safe on my car?

 

The W9 was from the WRX RA, around 260ps (240-250 bhp I think), and is very similar or the same as the Z5 ECU that also came from the WRX RA. The RA ECU will work just fine in an early WRX, just be aware that the RA was capable of higher engine speeds, Subaru fitted a stronger engine to the RA to cope with it. The ECU should give 0.9bar boost when in the redline, I don't recommend you try this too often, 0.8bar during normal driving conditions and better fueling throughout the rev range.

I have a Z5 fitted in my early WRX and it works just fine. Did my homework before fitting and it seems the general opinion is, as long as you do not cane the engine you will be OK. My WRX feels smoother, a good upgrade.

If you search for 'ECU' you will be able to read through all that I did.

Dan.

 

cool cheers mate,

maybe if i get this w9 i better fit a revlimiter too lol

my right foots quite heavy haha

thanks for info bud

 

Found this after a quick search.

U8 or W6 ECU is standard 1993/1994 WRX (JAP)
2C is standard 1994 WRX (a bit of a cross-over between U8/W6 and the Z4)
Z4 ECU is 1994-1996 WRX
STi ECU was SA
STi RA ECU was SB
STi 2 ECU was 6K
STi 2 RA ECU was 7K
WRX RA ECU are W9 or Z5
WRX Wagon 1C, 3B, V9
UK/Euro GT/Aus WRX Saloon & Wagon V7, 7D, 6D

Dan.

 

The U8 shouldn't be running 1.0bar

This is what a standard 93wrx ecu looks like.
0.5bar is limp home mode.

 

it is spose to be a chipped u8...

wot bar should it run?

 

standard is 11.47psi, dropping to 9.47psi at 6600rpm. With Fuel-cut @ 14.87psi. - about 0.79 psi.Depends on what chip you have in it best thing to do is to open up the ecu ,have a look and take a photo of ecu and post it to see if anyone can identify it.
If you do replace it try a standard ecu to see if it solves the problems you mentioned.
If you want more power easiest (but not cheapest) way is to get a remappable ecu

 

cool, how much should i be payin for a secondhand u8 (standard for my car??) ecu?

 

i've got a spare 1 you can have but would be easier for me to post after the New Year if that would help.
I would get your car checked by a good subaru specialist first (with a rolling road to check fuellin and boost) before getting a replacement ecu.
Have you reset the ecu at all?
Chris Palmer's Home Page

 

its been to subaru, they dont know wot it is, there computer says no... ha ha
i have reset the ecu a couple of times, after doin that it goes ok for a few miles then plays up again, its never flashed the cel light or given any fault codes

a spare ecu would be most appreciated thanks

 

If you pm your address i can send it but it would be after New Year when i go back to work (2nd Jan) if thats ok

 

Also worth checking if the soldering on the chip to the U8 board is alright

 

Instead of replacing the ECU - a much cheaper option would be to resolder 'J1' back in (ECU will then read internal ROM rather than the 'added' chip) this will identify whether the chip is causing problems.
Have you connected the diagnostic plugs to see whether a fault has been stored?

Cheers

 

myblackwrx has been very kind and is postin a ecu for me to try out, i dont want to start messin about with solder etc on my existing ecu, yeah ive done the diagnoses plug.. no faults..
its very strange

someone has sugested actuator..? but thought these either worked, or didnt..

 

In this case it would prolly be wise to find out what map is on the chip/s - the chip/s could be re-programmed with a more suitable map depending on what has been fitted - a piccy of the ecu with the top removed would be good.
The refitting of J1 is simply a link so not difficult to refit - can be done in minutes
What other mods do you have fitted?

Cheers

 

its got a de cat down pipe and a hayward and scott 2.5 inch straight through zorst, tried a panel filter and a cone filter, uprated fuel pump, not sure wot else...

 

if it drops to 0.5 bar on both ECU boost control and with a manual boost controller then I doubt very much it's the ECU.
The manual boost controller will over-ride the ECU and run whatever boost you dial it in to run. Unless of course you have a turbo fault or a dodgey hose somewhere.

check all hoses to / from the turbo and also check the hard plastic pipe from the turbo to the intercooler (if you still have it) as these can split.