Any ideas? Car hunts (only a tiny bit really) and sounds a little bit rough on revving up. Tried logging three groups whilst revving to see if it revealed anything. Any clues? I was thinking perhaps just the spark plugs needed changing. Car was a poverty spec 55 plate polo 1.2 with 80k on the clock.

Dirty throttle body? SWMBOs Leon did this until I cleaned the throttle body and reset it.

Check the brake servo pipe for cracks and see if there is a breather pipe running around the back of the engine, normally they clip into the inlet manifold. They perish and split.