low boost
 

Hi all, just wondering why my scoob has low boost. 7psi, its running about 290bhp, its a 93 wrx.. why I ask is my other scoob was running 14psi.. ive got the same ecu and everything else, any ideas

Checked all the boost pipes?

What's the reading at Idle?

Has someone changed bottom pipe on the 3 port?

no boost leeks, -20 on idle. no bottom pipe not changed. - 20 is what other scoob idles at too

Any faults stored?

no. ive even swapped the BCS.s over

Blow down the pipe the runs to the actuator, if you can blow, the diaphragm inside is gone. Swapped one over for a guy on Surrey at the weekend just gone.

will try that

done the above test. actuator working fine

Boost gauge plumbed into the wrong pipe.
Your reading actuator cracking pressure rather then manifold pressure.

Boost gauge plumbed into manifold

Well you won't be getting 290BHP from 7psi.

That's more like a figure generated by 16psi (and even that's if everything is top notch w.r.t MAF, Plug's, Coilpacks, Fuel Pump, Turbo and compression).

when it went to surry rolling road last year the print out says 290. but it had good boost then. its just dropped for some reason

Probably a knackered MAF then if the CEL hasn't come on.
Sometimes cleaning the MAF with carb cleaner will bring it back temporarily.

ok will try that, thanks

The early MY92-96 have a tendency to drop the boost target down to protect the car when it spots a MAF fuelling issue. It doesn't normally throw up a CEL either.

If you can boz one from someone else it could be worth a pint........

I have a maf from my classic, had it removed when daughterboard was fitted, was working fine before that.

if you need to test

I had this scott if you remember we fitted dawes device to compensate