Low boost, slow acceleration from 4th gear and up

Jun 19, 2024
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Recently got a car from a friend, a 2007 Legacy GT Spec B (CBA-BL5) JDM

It’s a 6 speed with a VF45 Turbo

For the past month or two it won’t go past 0.2 bar of boost, and things I have checked are:

Actuator and swing valve, which is normal and is closed and not like halfway open or misaligned, I even wired it shut and did a test drive to see if it would hold more boost but nothing changed, then took off the wire because thats obviously not healthy for the vehicle

Checked the turbo for a loose compressor wheel, exhaust side wheel but all is fine and no play and it’s not locked up at all. Spins freely with no problems.

Replaced and tightened all hose clamps concerning the intake system like intercooler, turbo inlet or inlet pipe, airbox, and such.

Did a resistance check on the boost control solenoid and it was proper 28 ohms.

Checked vacuum lines for like the BOV, BCS, PCV, and such. Replaced one that cracked when I removed it.

My main is I did the the clutch in this vehicle a year ago with new disk, cover, and release bearing, but not a new flywheel, and when I drive and let off the clutch quicker than usual and hit the gas, I get insane bucking of the vehicle every now and then and even the RPM bounces up and down

Could this possibly be due to the slave cylinder failing or needing a new bleed, possibly meaning that the clutch is basically like almost slipping while driving under load (boost)?

Any help or any questions I’ll be quick to answer

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