Impreza Sti 2003 lost power hlgh rpm

tomsti03 · 11-17-2020, 02:20 PM

Hi. I have European sti 2003 ej207 stage 2 340hp, as it turns out that one day it stopped blowing at high revs.
The car makes a small sound and the turbo pressure drops suddenly, going from 22psi to about 14 or less from an estimated 5200 rpm.

It is as if the engine does not suck or evacuate gases. I have changed the speed connector, coils, spark plugs, new gasoline pump, filter, checked the timing, I installed a fixed turbo wastegate, cleaned all the connections ...

It emits as a small blow and the turbo pressure drops suddenly, when before it reached 22 psi at cutoff. Turbo looks good

What do you think it may be?

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Scooby South · 11-18-2020, 08:30 PM

my first guess would be the Tune...the ECU controls the Boost controller and WILL cut if it reaches a certain level..
What are you using for Engine Management??
and What Turbo??? VF30-?? VF-22??
The other thing would be to check the wastegate actuator??? to see if its holding..
My guess is...its not holding the boost level you have designated for your Tune...

Someone else can chime in.. but those are my initial Thoughts..Good luck

Bill

Blackfin · 11-18-2020, 09:18 PM

Does the car still have a catalytic converter(s)? If so it may be damaged and causing a blockage.

Scooby South · 11-18-2020, 10:22 PM

Quote:

Originally Posted by Blackfin

Does the car still have a catalytic converter(s)? If so it may be damaged and causing a blockage.

Good call..

That definitely is a possibility..

Bill

tomsti03 · 01-09-2021, 09:55 AM

https://drive.google.com/file/d/1Y7v...ew?usp=sharing

Here's the log of the car. The car losses turbo pressure after 5000 rpm. The maf signal also drops and when this happens i hear a small hit sound.

I checked the syncronitation timing belt, changed the coil packs and spark plugs and no intake leaks.

The car was working fine and this happened suddenly, it has a fbo performance stage 2. Full exhaust 3", bov, walbro 340 classic stage 2.

kopele · 01-09-2021, 12:36 PM

Not sure what the sound might be, but I would check the boost controller, wastegate, and vacuum lines. Looks like it might be dropping to spring pressure, which most often is around 14psi.

Gucciflipflops · 01-09-2021, 05:28 PM

Possibly an exhaust issue. I think Steve Tuned on youtube had an issue similar to this and it ended up being something random in the exhaust system. If you have cats your cats could be going bad.

tomsti03 · 01-10-2021, 02:52 PM

Quote:

Originally Posted by kopele

Not sure what the sound might be, but I would check the boost controller, wastegate, and vacuum lines. Looks like it might be dropping to spring pressure, which most often is around 14psi.

Already discard all that, lock wastegate mechanically to see that it does the pressure and does exactly the same.

Regarding the exhaust system, I do not have catalysts. I have a complete line 3 "plus kakumei collectors.

11-17-2020, 02:20 PM	#1
tomsti03 Scooby Newbie Member#: 511743 Join Date: Feb 2020	Impreza Sti 2003 lost power hlgh rpm Hi. I have European sti 2003 ej207 stage 2 340hp, as it turns out that one day it stopped blowing at high revs. The car makes a small sound and the turbo pressure drops suddenly, going from 22psi to about 14 or less from an estimated 5200 rpm. It is as if the engine does not suck or evacuate gases. I have changed the speed connector, coils, spark plugs, new gasoline pump, filter, checked the timing, I installed a fixed turbo wastegate, cleaned all the connections ... It emits as a small blow and the turbo pressure drops suddenly, when before it reached 22 psi at cutoff. Turbo looks good What do you think it may be? * Registered users of the site do not see these ads.

01-09-2021, 09:55 AM	#5
tomsti03 Scooby Newbie Member#: 511743 Join Date: Feb 2020	Log inside https://drive.google.com/file/d/1Y7v...ew?usp=sharing Here's the log of the car. The car losses turbo pressure after 5000 rpm. The maf signal also drops and when this happens i hear a small hit sound. I checked the syncronitation timing belt, changed the coil packs and spark plugs and no intake leaks. The car was working fine and this happened suddenly, it has a fbo performance stage 2. Full exhaust 3", bov, walbro 340 classic stage 2.

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11-18-2020, 08:30 PM	#2
Scooby South Subtly Outspoken Moderator Member#: 238 Join Date: Sep 1999 Chapter/Region: MWSOC Vehicle: OG05 STi 51E	my first guess would be the Tune...the ECU controls the Boost controller and WILL cut if it reaches a certain level.. What are you using for Engine Management?? and What Turbo??? VF30-?? VF-22?? The other thing would be to check the wastegate actuator??? to see if its holding.. My guess is...its not holding the boost level you have designated for your Tune... Someone else can chime in.. but those are my initial Thoughts..Good luck Bill

11-18-2020, 09:18 PM	#3
Blackfin Scooby Specialist Member#: 361325 Join Date: Jul 2013 Chapter/Region: E. Canada Location: Ontario Vehicle: 2010 STi Dark Gray Metallic	Does the car still have a catalytic converter(s)? If so it may be damaged and causing a blockage.

01-09-2021, 12:36 PM	#6
kopele Scooby Newbie Member#: 363007 Join Date: Jul 2013 Chapter/Region: MWSOC Location: MO Vehicle: 2008 STI Black	Not sure what the sound might be, but I would check the boost controller, wastegate, and vacuum lines. Looks like it might be dropping to spring pressure, which most often is around 14psi.

01-09-2021, 05:28 PM	#7
Gucciflipflops Scooby Newbie Member#: 521349 Join Date: Dec 2020 Chapter/Region: South East Vehicle: 2005 Impreza WRX	Possibly an exhaust issue. I think Steve Tuned on youtube had an issue similar to this and it ended up being something random in the exhaust system. If you have cats your cats could be going bad.