*Urgent* STI ECU numbers - how to tell its an STi V5/6 ECU??

[Guest]

I am having the same prob in my coupe, and its driving me nuts!!!!

[gazzy2000]

 STi-TypeR said:

I am having the same prob in my coupe, and its driving me nuts!!!!

Yea? what did you do for the problem to come about? is it a V5/6?

[Guest]

Hey man, nah its V4 with 3port solenoid and i think its been like that ever since I bought it, now after the build i put a gauge on it to see what its doing, wont go over 10psi and its rock solid in each gear... totally stumped have tried a few things but can't pin point it yet.

[Guest boostin]

V5 and 6 will happily run 1.2bar, and don't boost cut until 1.5. I reckon its picking up a knock and pulling boost.

[gazzy2000]

 boostin said:

V5 and 6 will happily run 1.2bar, and don't boost cut until 1.5. I reckon its picking up a knock and pulling boost.

Good point, i have read about knock sensor relocation, very comon on the UK forums, also i have a V4 STI knock sensor i cud try that too

EDIT: i did relocate the knock sensor as per the UK forms (i forget the link now) on my V4 STI and it fixed a lot of problems, they can be hyper sensitive and the location they tell you to put it on is not that far away that its not going to pick ups knocks, just away from the area where vibrations are aplenty

EDIT - for my ref really: Disconnect the battery negative cable, Remove the intercooler and the knock sensor is located top -back of engine block, Disconnect the knock sensor connector, Remove the knock sensor from the engine

block.Install the new knock sensor to the engine block.

Tightening torque:

NOTE:The extraction area of the knock sensor cord must

be positioned at a 60" angle relative to the engine rear.

24 N.m (2.4 kgf-m, 17.4 ft-lb) Connect the knock sensor connector,Install the intercooler,Connect the battery negative cable.

[gazzy2000]

heres a link with the knock sensor relocation sugestion, there are others i will find em and post

http://www.justanswer.com/questions/25vzm-impreza-turbo-knock-sensor

[gazzy2000]

 gazzy2000 said:

heres a link with the knock sensor relocation sugestion, there are others i will find em and post

http://www.justanswer.com/questions/25vzm-impreza-turbo-knock-sensor

this is the link, the one fix that made my old STI run like a absolute dream, will do the same on my BH tonight

http://www.imprezasport.net/forums/index.php?showtopic=785&st=0

[Guest boostin]

The knock sensor works fine in the factory location. If it is actually detonating, you want the sensor to pick it up. However I have also seen cambelt tensioners bounce and rattle on the base plate and the sensor picks this up as a knock.

[gazzy2000]

OK just tried the Knock sensor relocation, reset ECU and same deal.... boosted to 15 then hestitated and back to 10 again :'(

I am now thinking AFM mismatch??

[99GTB]

Your gtb afm is identical to a v5/v6 afm.

[gazzy2000]

can any one tell me what sensors the ECU relys on that would knock back the boost to actuator pressure (limp boost mode)?

i know mechanically how the boost is controlled and am 100% certain its plumbed right, but this problem points directly at the duty cycle of the boost solenoid (wastegate solenoid) of which is controlled by the ECU so somethings gota be telling the ECU to backoff the boost.

[Guest]

have you tryed the knock sensor thought?

reset the codes, and i think if you unplug the knock sensor and give it ago, you might need the knock sensor pluged in, which means you will have to relocate it, if this works, then you have DET issues.

However ther is something you might try with no gaurenteed results.... try to relocate the sensor to the top of the engine block where it meets the bell-housing there is a threaded bolt hole that fits the bolt in the knock sensor perfectly. This will reduce the sensitivity of the sensor and reduce the occurences of the "check engine light" coming on.

Read more: http://www.justanswer.com/questions/25vzm-impreza-turbo-knock-sensor#ixzz0W87G01UO

[Koom]

 gazzy2000']

[quote name='gazzy2000 said:

heres a link with the knock sensor relocation sugestion, there are others i will find em and post

url]http://www.justanswer.com/questions/25vzm-impreza-turbo-knock-sensor[/url]

this is the link, the one fix that made my old STI run like a absolute dream, will do the same on my BH tonight

http://www.imprezasport.net/forums/index.php?showtopic=785&st=0

Nice one Smurff

[Guest]

lol, little hung over today, my bad

-smurff

[gazzy2000]

forum with same issue on NASIOC

http://forums.nasioc.com/forums/showthread.php?t=959190&highlight=%2Awont+boost+past+10+PSI%2A&page=2

[gazzy2000]

i have a theory that i am going to try.

Maybe a crack in the intercooler...... because wen we tried a MBC it boosted to 15 fine but was very jerky, i.e. the MBC obviously was letting boost get to 15 but if it had a leak the boost would hold at 15 thanks to the MBC but would be forever fighting to keep it there as the boost leaked out, like a crack expanding due to the pressure build up.

I have the original TT TMIC so will try that, soon, i have my chores to do first :'(

wot do ya reckon?

[gazzy2000]

 gazzy2000 said:

i have a theory that i am going to try.

Maybe a crack in the intercooler...... because wen we tried a MBC it boosted to 15 fine but was very jerky, i.e. the MBC obviously was letting boost get to 15 but if it had a leak the boost would hold at 15 thanks to the MBC but would be forever fighting to keep it there as the boost leaked out, like a crack expanding due to the pressure build up.

I have the original TT TMIC so will try that, soon, i have my chores to do first :'(

wot do ya reckon?

nup, wasnt that.

I am going to try a AFM next, failing that i am going to borrow a Bosch monitor and go for a drive with an "on to it" auto sparky mate (considering i have been out of the game now for a 9 years)

[gazzy2000]

Hey does anyone know if a knock sensor throws a CEL only when the sensor itself is stuffed or when it detects knocks, or both?

CHeers

[Guest boostin]

Only when sensor resistance is outside spec.