Intermittent loss of power

Hi, Been following tips from this site for a couple of years so perhaps it's time to sign up!

I have a notorious BKD series six-speed Octavia. (Oil pump failure ~ new crankshaft and shells etc at 61,000 miles, new turbo at 95,000 miles and a host of other issues!) The latest though has the garage sussed. I hope someone here can help.

Occasionally I will lose power when accelerating. When this occurs, fuel economy also drops (from c.60+ mpg to 50mpg). Switching off the engine and restarting usually resolves the fault. The car has only done 8,000 miles since the new turbo was fitted but it did not exhibit this symptom before it was changed. Whether related I don't know but two weeks ago when I put my foot down to overtake, there was a loud bang and total loss of power. The turbo hose had blown off the intercooler. Thrashed it around the lanes today (average 2500 to 3500 revs) and apart from an initial hesitancy at low revs when cold, it was fine. Suggestions please?