Engine problem Lib GT-B

[thissoan]

Just in the process of replacing the AFM. Will look at knock sensor next.

[thissoan]

Just as a follow up to my initial thread.

Took the problem to Subaru Docklands Sti. They looked and test drove the car and officially have stated to me that they cannot find any performance fault or ecu error code when running diagnostic tests. There is no issue for them to rectify under warranty obligations.

Unofficially and on the quite,they pointed out that the car has been modified from original spec due to the instalation of the quad pipe Hitech diffback mufflers. The modification has altered the system backpressure producing an overboost state. The ecu as a result has been retarding the ignition to bring boost under control.

This is what has caused the loss of power on load and higher fuel use. They advised to get an ecu tune to account for the change in backpressure and reparameter the ignition mapping and recomended their tuner Vin.

Any comments or simular experiences.

Thx

[coyote]

The modification has altered the system backpressure producing an overboost state. The ecu as a result has been retarding the ignition to bring boost under control.

That is complete, total and utter bollocks.

[sharpie]

like i said spend the $50 refit the original mufflers. My time spent on your car wont be honored under warranty if the hitech mufflers remain. There is no issue with the knock sensor, i checked.

[sharpie]

The modification has altered the system backpressure producing an overboost state. The ecu as a result has been retarding the ignition to bring boost under control.

That is complete, total and utter bollocks.

nfi.

[thissoan]

Hi Steve,

Welcome aboard. Thx for looking over my GT. Not forgotten for your time and advise. Still have the ignition retard issue, gets better when i use 10%/90% ethanol/petrol mix.
Got a few other priorities at the moment, will try to sort issue out with or without cans sometime in near future.

see u around.

Pete

[buddha21]

Hi all, I just brought a 2008 Liberty Wagon Gt spec b tuned by STi. After getting the car registed in my name I have found out that the car has had a rebuild and has different engine numbers. They said at Subaru Australia that it was a bottom end problem, a knocking noise. Is this common problem or one off?? It only happened 5000k's ago and under warranty. Also should i be happy that is a new engine or mad that i may have been taken for a ride and not completly done my research.. Thanks for the help!!

[senator]

Hi all, I just brought a 2008 Liberty Wagon Gt spec b tuned by STi. After getting the car registed in my name I have found out that the car has had a rebuild and has different engine numbers. They said at Subaru Australia that it was a bottom end problem, a knocking noise. Is this common problem or one off?? It only happened 5000k's ago and under warranty. Also should i be happy that is a new engine or mad that i may have been taken for a ride and not completly done my research.. Thanks for the help!!

Its happened before, according to Subaru some parts were not correctly cleaned after machining stage prior to assembly at the factory.

They would of replaced your short block resulting in a new engine number

[coyote]

The modification has altered the system backpressure producing an overboost state. The ecu as a result has been retarding the ignition to bring boost under control.

That is complete, total and utter bollocks.

nfi.

I don't know whether the fact we now know you were not misquoted is a good thing or not.

I tend to respect people a lot more if when they don't know the answer to something, they say so, rather than making stuff up. I understand it's your job to tow the company line while you are at work, but on here is different.

I don't know if you made that explanation above up yourself, or you got it from Vin, but it's really just a way of saying "I don't know what the issue is, so I'm just going to try and baffle you with bullshit".

And before you come back with another three letter response, I've got a pretty good idea how both the boost and knock strategies of these ecus works. A much better idea than I think you do anyway.

So, if you'd like to help this bloke, tell us what you actually observed (rather than what you just made up) and to the original poster ... buy yourself a tatrix cable and I'll tell you what to log in order to get some idea of what's going on.

[thissoan]

i see what you say coyote, can you give me more info about your what you think.