My car has developed a new problem. Some times when passes about 3,000rpm it hesitates as if it has cut out and bump started itself again and does it a few times until it gets higher up the revs. When it does it no dash lights come on and the boost dropps completely but you can hear the turbo is still spinning. The EML is on but with the same old fault codes due to the lack of an ABS pump. Ive changed the plugs and as far as I can see there are no boost leaks and there is nothing in the way of the actuator. Any ideas?