Guys,

I have an 02 STI UK with PPP, and have developed a severe flat spot at about 5750 RPM, lasts a second or two and I'm not sure it happens in every gear, had the car with the dealer, and they don't know what it could be.

Anu Ideas?

Andy

[Edited by Andy W STI - 10/22/2003 10:41:24 PM]

 

What fuel you running?

 

Shell superplus (no optimax over here I am afraid). Normally with an octane booster also but not in the last 3 or 4 tanks.

 

Get DeltaDash on it - could be pulling timing because the ecu is either seeing, or thinks it's seeing, knock.

Richard

 

Already saw that on mine while testing different engine management configurations.
The ECU retards timmings exactly between 5650RPM and 6150 RPM, given a big acceleration feeling after 6200 RPM. This is frequent on STi7.
Don't know about what PPP does, but could be due to a too high boost, too lean fuel mixture or bad timmings.
perform a Daltadash log on it to know more about that.

 

Subaru swap such ECU's out under warranty here in Switzerland, it's the only thing that seems to fix it.

Richard

 

I thought the ECU ignored the knock sensor over 5k, but as you describe it sounds exactly like symptoms I have,flat then a big surge at 6250rpm. I have noticed that very thing since I bought the car new, before and after PPP but it is much more noticable now.
Pity I know of no-one with DD over here.

Cheers Guys

Andy

 

Where are you? I never heard of anyone in the UK experiencing this issue.

Richard

 

I'm in Northern Ireland.

Andy

 

I'd try and get a dealer to go out with you monitoring knock correction (I assume the select monitor can do this?). The worst I've seen is -11 degrees in a region that would normally be running +4-7. I never measured it, but assume this would create some fairly high EGT's as well as making it flat as a pancake.

Richard

 

cheers

 

I had many Select Monitor/Delta Dash on mine.
On all of them, you can see the ignition timing suddenly decreasing down to 20° at about 5600 RPM and increasing again up to 30° at about 6200RPM. In the same time, knock correction is decreasing down to 3° and increasing again up to 8°.

Then when you have a look at the overall ignition timming which corresponds to the summ of them, ignition decrease suddenly from 30° down to 23° at 5600RPM and increase to 38° at 6200RPM. It is then quite stable over 6200RPM.

I don't think this is due to detected knock as my knock correction keeps to be positive. But it's true that a so low timming between 5600 and 6200RPM give a feelling of acceleration stopping. Then over 6200 RPM, the high level of timming give back a big acceleration feeling.

Why ??? this is typical to STi7 and I beleive that it's a bad ECU programmation from Subaru. Seems to have desapear on STi8 !

 

Email me if you like - where in France are you? I assume you've at least raised the boost - the only one I saw doing it stock I refused to remap.

Subaru CH replace faulty items with an AG821-2593; you probably have an AG820-2591 or 2592.

The maps look exactly the same, EcuTek confirm the code is the same too. Fixes the problem though

Having done a few STi8's now, they feel remarkably similar to drive....

Richard

 

You have a mail with different logs and EXEL files ;-).
I raised the boost on mine as you will see, as well as fuel mixture modification.
I also saw that this problem disapears when boost level doesn't go above 1.2 bar and Fuel mixture is reacher (+4% in fuel) between 5600 and 6200 RPM.
On a full stock STi7, it shouldn't appears except on some with decat exhaust...and it seems to appears when the car reaches about 10 Kmilles !