Boost not going past 1.1bar

[mengz]

Hi All,

i have a GDB version 8 subaru impreza wrx sti. my car has been boosting at 1.5bar all the while and suddenly 1 day, it just didn't boost pass 1.1bar. it does not spike, it does not creep, it just holds steady at 1.1bar and refuses to go up.

thought my boost meter faulty, had the car on the dyno at APD and it shows the same 1.1bar max as well.

Below are the diagnostics done:
1. check wastegate diaphragm, no leak. wastegate is able to hold.
2. bypass oem boost solenoid, boost still wouldn't go pass 1.1bar.

replaced intercooler gaskets, bov gasket, downpipe gasket and a few gaskets here n there. still same prob. checked the turbine shaft, no freeplay.

mech is suspecting that the compressor fins might be damaged or worn out. hadn't had the turbo removed to really inspect though.

hope to get some feedback or advice here.

Thank you.

 

[mines998]

Could it be minor leak on yr intercooler piping? Boost controller already check?

 

[mengz]

Could it be minor leak on yr intercooler piping? Boost controller already check?

That's y afraid might have minor leak somewhere. Need to really check. Thank god mine is tmic, so the piping is short.

Boost controller already tested. Bypass it same result, swap with another boost controller also same results.

 

[Yee]

U pump your petrol at the same station?
Many of the Subaru owners had experienced this, happened to myself few days ago.. Not sure if your's the same problem.

http://www.mysubaruclub.com/phpbb4/viewtopic.php?f=32&t=297

 

[frootloops]

petrol RON pun got tipu ka?

 

[clockwork]

mean different petrol station give different quality of petrol ha bro?

 

[Dayline668]

Not tipu ron, fuel quality bad. Maybe is running in safe mode, try resetting the ecu.

 

[mengz]

If it's in safe mode, boost will be at 0.5 bar only. That's the safe mode boost for scoobie, I kena before while running on Ron 95. But now I can boost till 1.1bar max and the car is making 275hp on wheel. Afr is good.

At safe mode the afr will be one flat line at 10.0:1

 

[clockwork]

same like mine bro also just set n tune to 1.1 bar...

 

[mines998]

same like mine bro also just set n tune to 1.1 bar...

Bro I tot u Mia now show up..

 

[Dayline668]

If it's in safe mode, boost will be at 0.5 bar only. That's the safe mode boost for scoobie, I kena before while running on Ron 95. But now I can boost till 1.1bar max and the car is making 275hp on wheel. Afr is good.

At safe mode the afr will be one flat line at 10.0:1

But hav u try resetting the ecu..? Data logging should point out the problem, show me the data n i can help u point it out.

 

[mengz]

But hav u try resetting the ecu..? Data logging should point out the problem, show me the data n i can help u point it out.

Removing battery cable can reset ecu? I'll give it a try.

The last time my tuner/mech datalog got no errors.

I think I need to send to another workshop for 2nd opinion.

 

[Dayline668]

Removing battery cable can reset ecu? I'll give it a try.

The last time my tuner/mech datalog got no errors.

I think I need to send to another workshop for 2nd opinion.

If the mech say no problem then y is the car still problem..? better get second or third opinion rather then change all the part in your car. Newage subaru ecu only will reset via OBDII port.

 

[ixeo]

Removing battery cable can reset ecu? I'll give it a try.

The last time my tuner/mech datalog got no errors.

I think I need to send to another workshop for 2nd opinion.

i got a scangauge 2 if you want to scan it yourself. give me a call.

 

[flanker c]

beware guys...nowdays got some of petrol pump station conn RON97..they fill RON95 for fast buck! yeah we are pay RM2.80/Liter for suck ron95!! WTF!! i got kena before after fill RON97 my ride got knock...more 3 time i kena..luckly my PFC ECU has KNOCK monitor.. beware guys most pump station out there do dirty job expicially SHELL and CALTEX..untill now i only use ESSO ron97...i can see ron97 esso fuel is BLUE COLOR...or PETRONAS primax97...

 

[mines998]

Any specific area to beware?

 

[Yee]

Not sure ur's is the similar case, but as for me, mech couldn't manage to diagnose the problem as well. Therefore, I suspect the bad quality of fuel was just quite minimum to trigger the ECU into save mode. However, after i refuel the problem solved. Have u check ur fuel filter?

 

[mengz]

Mine is definitely not fuel prob as my car is not knocking and making good power at 1.1bar.

Fuel filter also changed 15000km ago.