Engine Mechanical problem
2000 Vauxhall Vectra 4 cyl Two Wheel Drive Manual 44,000 miles

Car has started losing power, it was fine but now mainly when just going into 2nd gear i.e pulling off at a roundabout it loses all power for a couple of seconds and then kicks back in!. Very dangerous ?, But can do it any time. Have tried injector cleaner,fitted new spark plugs , also no engine managment light on.