Why would the engine die while driving and start again?

Answer 1

This depends on whether the vehicle is gas or diesel fuel. A gasoline powered vehicle can have this fault if the fuel pump is failing. This causes the engine to "cut out" at high RPMs, when more fuel is required. It can also fail if the ignition coil is failing. When the coil is failing it tends to overheat during prolonged driving and cause the engine to stall. Diesel vehicles can either be caused by a failing fuel pump, water in the fuel filter that needs to be drained or a break in the wire powering the injector pump solenoid. If you happen to own a Nissan Serena with a SD20 engine, watch this spot. Mine has just started to exhibit those symptoms and I will be sure to update this answer as soon as the dealer has finished checking mine.