hi i have just joined this forum so i apologise if i am not doing this right but here is my problem .i own a 2003 audi a4 1.9tdi estate it runs like a dream until you hit 70mph then it pulls back and loses acceleration as it slows down if you change down the gears and try to increase speed there is nothing there .if i pull over to the side of the road switch the engine off and restart again everything is fine and the acceleration is there again please help its doing my head in