NJL555

I have a uk turbo 2000 impreza, when accelerating the boost on the gauge goes up to 1.1 bar as it should and then moves back and forth from 0.5 to 1.4.
You can feel the power dropping on and off with the boost gauge disconnected also.
Have had various tips from other people but still cant cure it.
Have had a brand new boost control valve fitted on the left inner wing, have cleaned out all the bleed pipes with cleaner several times,checked all boost pipes for leakes, new dump valve fitted,had complete exhaust system off and checked for blockages, disconnected bleed pipe onto turbo and roadtested so i know the turbo and accuator work(shuts injectors down at 1.5 bar),there is a small olive in the turbo bleed pipe which is 1.2mm that is not blocked.
Am running out of ideas, has anyone had this fault some more info would great as it has been like it for some months now.
Many thanks

Greeno

Could be retarding the ignition due to det...???

Have you chekced your MAF...???

G.

NJL555

Hope im not being thick but what is "MAF" ?

WallacePerformance

Could be knock sensor..... Do you get any warning lights on the dash?

Gavin

NJL555

No have never had any warning lights up.