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2000 Forester S/tb
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36 Posts
Discussion Starter · #1 ·
Hi all,
m having issues with the boost level on the car. Sometimes, when it feels like, I get a consistent boost level of 0.7, but of late it has been boosting at 0.4 only. Any ideas what I can look out for?

thanks
 

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2000 Forester S/tb
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36 Posts
Discussion Starter · #2 ·
okay, so I took the car out over the weekend for a long drive, and it was reasonably well behaved, boosting at most times at 0.7..... initially I had thought maybe the fuel octane levels were probably to blame, but now.... m stumped! when we I got back to regulare city driving, boost is back to 0.4???
By the way, if you're running lower octane level fuel in the car, can this cause what someone called a "slow knock"?

thanks
 

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2000 Forester S/tb
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36 Posts
Discussion Starter · #3 ·
ok,... so yesterday, I disconnected the pipe that goes to the controller (I think thats what it is), and the boost goes up to about 1.0 bar, but of course I can't run the car that way. So the turbo is working properly, and I had also thought it might have been the fuel, nut if the car is boosting that way, maybe it isn't.... so now m stumped! any ideas?
 

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99 UK S-turbo
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8,566 Posts
What model?

Max boost on EU S-turbo/Oz GT's is 0.5 bar, not sure about JDM S/TB and T/TB.

The EMS will reduce boost if it sees knock or very high intake air temps, then it will fall back to wastegate boost (probably about 0.4bar).

If the BCS is sticky and not opening then you'll again only have wastegate boost.

Simon
 

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2000 Forester S/tb
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36 Posts
Discussion Starter · #5 ·
Thanks Simon, appreciate the response.

forgive the ignorance, but what is:
EMS and BCS? Also, the model, it's a 1999 Forester, not sure about much since it didn't come with Owner's manual (second hand car)... what I do know is that the engine is EJ20.... does that help? As for the boost, before I had this issue of moody boosting, it would boost at 0.7 bar most of the time.

sometimes it "opens" up and boosts at 0.7 for a few seconds, but, if I keep my foot down, it drops to 0.4 and then doesn't come back to 0.7 for another day or so......
thanks
 

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Don, King of the parts diagram
MY11 WRX STi Sedan 6MT
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5,984 Posts
forgive the ignorance, but what is:
EMS and BCS?

EMS - Engine Management System (ECU)
BCS - Boost Control Solenoid

ECU - Engine Control Unit
 

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Registered
2000 Forester S/tb
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36 Posts
Discussion Starter · #7 ·
Thanks Don. Okay so is there a way I can clean the BCS? just to make sure it isn't the one causing all the problems? as for the EMS, I need someone to "plug into the car" to look at that?

thanks
 
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