Vauxhall Zafira engine cutting out and not able to restart for several minutes

While driving around town (upto 30 mph) the engine will suddenly die. The car will still move forward while coasting. The engine will then not restart until after 4-5 minutes. I did notice that it died at one point as soon as I hit 2000 rpm. Although my wife has had it die while waiting for lights to change. The breakdown man could not find any faults from the diags although he also had it die while idling. He suggested either fuel pump or crank sensor. Any thoughts