I've just had a fuel pipe replaced which required manifold off. However now I'm only seeing 7 psi boost.

Any ideas? I've had a hunt round and can't see any pipes off? is the actuator / solenoid not seeing the right info?

 

Check the vacum line that comes off the turbo to the T piece, this should have a small brass restrictor in it. If this is missing or the pipe has been replaced with new pipe with no restrictor in it, you will end up running at manifold pressure, i.e around 7psi.

You can replacmnet restricotrs (Orifaces) from subaru or any specialist.

 

if this pipe is damaged / split would it have the same effect? I know the ones you mean.. manifold to t piece then to actuator and solenoid.... the intercolooler (which is an sti one on a bugeye wrx) is VERY close to this pipe.. I'm wandering if this has been damaged when the intercooler was put on

by the way it's a uk bugeye WRX running PPP so I think the restrictor has a smaller hole too IIRC

 

Not 100% on what size the restrictor should be, i`d imagine either 1mm or 1.2mm, i run a 1.0mm on my Blob JDM Sti. If its damaged it may be causing it, but if it was split badly then there would be no pressure acting on the actuator at all and boost would be too high.... i think... it all gets very confusing!