Can anyone help me with an annoying boost problem please? , My small turbo escos is misbehaving . Basically, when I floor the accelerator, it is fine , it goes into over-boost (about 1.2-.1.3 bar)then drops into the windowed area (approx 0.9 bar) as it should do and holds. However, if I part throttle the car, i.e 3/4 of the throttles travel, the car will accelerate to the throttle setting, then if I hold it constant the boost will swing slightly over, then slightly under and slightly over again repeatedly . I have replaced the re-circulation valves diaphragm, and the turbo is brand new (2000 miles inc a new actuator), all the tubing to the the amal valve, actuator and re-circ valve from the inlet manifold is perfect, and I really cannot think what else it possibly could be Has anyone got any suggestions please